I would not change original features if they are intact, but since that middle window has been altered recently, I think the best option would be to replace the 3x3 center with clear old glass, either in panes the original size, or as one piece--either way was done in the period.
As for your balcony, I'd seriously not do that--such a balcony done as it is, is a strong feature of the style--if you alter it as you suggest, that will not fit anymore and will throw off the entire design of the house. I've pored through dozens of design boooks from the period, and no balcony like that has an open railing--and if there was fretwork, it was part of an eave design with no balcony below. With those windows being recessed as they are, I don't think you would gain enough light to actually justify such a drastic change.
Why not use the balcony as it was originally meant--as a place to sit out in the open, but still protected from the elements? If there isn't space for a chair or two, why not cushions? I would love such an alcove to read on a sunny day, or to view the scenery at dusk!

Good points, thanks.

Interestingly, the original blueprints call for a railing on that balcony; I'll try to scan. I have photos of the house before it was sided showing a solid knee wall though--perhaps a time- or cost-cutting measure.

Your point about keeping original details made me suddenly wonder--is any of this stained glass original? Now I've got to pour over the old photos, and maybe even call the po's--luckily we are on good terms, even if we don't see eye to eye stylistically.

Thanks!

But if the glass was originally clear, would you vote for a return to all clear, or one of the other options I listed?

What's so sacrosanct about old homes that you daren't change them?

The trouble is that subsequent owners often don't have a clue about architecture or design but do firmly know what they like.

As the OP suggests, I think the "room with(out) a view" is precisely one of those latter dubious improvements.

Slateberry, from your pics, I'd say the two side windows and the area around the pause marks is original--the colors look right, and it is a pain to change out old glass with stained--I've done that on my main parlor window--as high up as that looks, it would be even tougher--so I bet it's original. As to the balcony, do the prints show spindles, or are they just calling the knee-wall a railing?
Worthy, the big draw in old homes for most buyers IS the original details--they are unmatchable today without huge cost--and add significantly to resale value if they are still there for the next owners. Don't care about stuff like that, then why are you in such a house? Newer is usually cheaper to keep up; don't care if you risk losing prospective buyers by altering your house's original details--then go ahead and kiss your dollars goodbye.
As to style--old houses tend to be well-built and appeal because of their design--and that is something which anyone can appreciate--don't you have an idea when something appeals to you or when it doesn't? If you change exterior features a house just won't 'look' right, and the parts which don't fit will become obvious as you look hard at a place.
Most old house buyers have a basic idea of what fits or appeals to them, and want houses which preserve as much of that charm as possible. I had a vague idea of the different styles, but I educated myself during my years in my house--you just need to look at a few plan books to get an idea; the one thing I KNEW when house hunting was this: I grew up in a 50's ranch, and would never buy such a house for myself--I had to have two stories, and something with some character inside, not just boxes with basic trim as I'd grown up in.

OK, I'm not trying to play nice or anything, but actually I agree with both of you, espcially worthy's "don't have a clue about architecture or design but do firmly know what they like." In this case, I do have a very strong opinion about what I want to do, but I'm trying to temper that with good taste and what's appropriate for the house. Countless times I've wished that others felt the same way.

But as much as I value preservation and stewardship, I'm also very guilty of doing things my way: for example, the dining room is used as a living room, and half of the double-parlor is used as a dining room. This is because the plan dining room faces east, and I like to enjoy the daylight as long as I can. The room we use as a dining room faces south, with a bay window; it is flooded with light all day, and a nice glow in the evening. Both rooms are the same number of steps from the kitchen.

But in questions like this, where the changes are harder to reverse or restore, I like to bring it to this forum before I move ahead.

I'm leaning toward clear middles with a single-grid width of color around the border. I have seen other houses around here with windows done that way.

old houses tend to be well-built and appeal because of their design

Some are. Many aren't. Like the ones friends have stripped to the frames that were obviously banged together from scavenged scraps a century earlier.

I have no compunction in demolishing mass-produced 20th Century homes.

I am as appalled and puzzled as the next person by homeowners who scrap solid wood doors for hollow mahogony units and foot high baseboards for two inch poplar and smash cast iron soakers to make room for thin steel tubs.

I immediately had a feeling of claustrophobia when I saw the stained glass windows.

Even assuming the windows are original, this is your home and a space you use, not an museum. I don't think you are beholden to the windows because they are original. And just because they're orginal doesn't mean it was a great idea to begin with. We change our old houses all the time--indoor plumbing comes to mind.

Can you replace the window or windows with what you want and leave the old ones in tact for a future owner to do with what he or she wants?

Worthy, you are pushing my hot button when you talk about hollow-core doors! If you only knew what I've been going through to restore the bedroom doors in our house--but that's a post for another day.

Acc0406, thanks for the validation. It's funny, if the view were lousy, or blocked by an adjacent building, the stained glass windows would be great. I wish I could find another place to use them--will have to think about that one. I wonder if most houses got stained glass windows where light with privacy was desired, or a bad view was being blocked? That would be an interesting thread.

From what I've read in period decorating books, stained glass depended on the budget of the owner/builder...leaded glass was another popular option.
Stained glass could have been used to hide bad views, but in a lot of houses, it was a sign of prosperity, placed in the principal rooms such as a foyer, parlor or dining room.
A friend's house has stained glass in her front parlor--but only in the top third of the window--her house was built around 1870. My own house has it in a sidelight and the transom above the front door, which has bevelled glass--my house was built in 1908. My parlor's front window has diamond panes above one large single, and I switched out the diamond-shaped clear panels for three colors of stained glass, and am doing the same for the dining room which is the same style.

I'm with the OP on checking out the view out my windows. I always took pictures of my windows from the inside looking out, so I could then garden to improve the views.

And I also agree with Worthy, that there is nothing sacred about an OLD house just because it was that way when you found it. Some homes are historic, but most are not. And the OP stated that a PO liked to do stained glass work, and made changes in the windows of the room currently her office.

One possible option for changing the glass panes is to put the colored rows of glass into the openings across the TOP of each window. I note also that there are some panes that are clear but wavy finished. Those could go down the sides of the two outer windows. In the rest, I'd do clear maybe bevelled panes.

As far as the demilune balcony, Someone may have had a baby or young child, and the solid perimeter was safer. I would definitely think of putting an open railing there. And if it is deep enough, how about a nice old fashioned macrame hammock or a bistro table and chairs and a wicker chair and ottoman....I think it would be period authentic that way.