I'm going to try to find this for you,
So far:
http://www.gascoignelumber.com/millwork.html
Kind of small.

OK, found a supplier:
http://www.madriverwoodworks.com/catalog/2006_catalog.pdf
go to page 25!
Casey

Here is a link that might be useful: mad river woodworks

Casey! I think I love you. Haha. I've been trying on and off for a year now and never found them. Thank you SO much.

Actually since you've posted this before, I thought of you the other day when I found some similar to this at a local lumberyard. Subsequent to that I discovered a local millwork shop where they specialize in stock and custom heritage trim - and they don't have a website.

I also just mail-ordered some $1.95 lamp parts from a US online supplier, where there was a $50 minimum order and they wouldn't ship to Canada I (used a receiving office in the US). Subsequently, I found the parts I wanted on the rack at a local lighting store - that doesn't have a website.

Moral is, the web is still no substitute for getting out and asking at your local vendors, even if you have to phone and then fax or email them a photo. Glad it worked for you this time, but you might also find them closer to you than you think... the yellow pages still rock!

KarinL

Karin, I have been looking in/calling local stores for over a year now! I emailed photos to several places but they all want to charge a very expensive knife fee, I think it was called. Not once have I seen them in store around here. That's why I said I am at a loss. I'm not just at a loss because the web has failed me, haha.
Would you mind sending me the name and location of the stores you saw them at, so I can compare prices with the link Casey found? Thanks!

"...but they all want to charge a very expensive knife fee, I think it was called."

They do not know how to actually make them very well.

A knife that large will indeed be very expensive, and leave a poor finish from the wide range of cutter speeds from the middle to the edge.

They are not really rosettes anyway.

Any decent wood turner should be able to make them pretty easily.
Four pieces of wood are glued together with paper in the glue lines so they can be separated later without actual cutting that crates a kerf.
The face is then turned on a lath to the correct profile.
After some clean up on the lath the pieces are separated on the glue lines and the lines lightly cleaned up (a plane or scraper is all that should be needed).

In a volume environment it would be easier to use a shaper knife as a scraper to form the profile.

You could look around for a local wood turners club and see if anyone is interested in making you some pieces.

The ones I saw may not have been quite the same; if these are, I would grab them! Plus, I'm in Canada. But when I can get a photo of what's here, I will.

The heritage millwork shop near me makes all its profiles slightly scaled down from the original to work with current sizes of stock lumber - so check the size at your CA shop too.

Karin

Thanks, Karin. Don't worry about a photo, but I appreciate that you would try to do that. Half of my doorways don't match to begin with! Haha.
Mad River just got back to me and they are $10.70 a piece, so that works for me!

I don't see why they couldn't be made on a shaper with a rotating jig/holder. Yes, there would be some tearout, but it doesn't seem to bother the stair rail makers; this is the same way that rail goosenecks are molded.
Casey

"I don't see why they couldn't be made on a shaper with a rotating jig/holder. "

Curve is to tight.

I got some for my house from this place up in Maine. They were great to work with:

Here is a link that might be useful: Harttwood

I finally ordered them! I decided on a different casing, so Tim from Mad River Woodworks is going to custom make the corners to match both the new casing as well as the style of the other casings in the house. I didn't get to recreate the same look, but I think it's a good compromise. I can't wait for the shipment to arrive!
Here's a pic of the new casing:

I have the SAME moulding, and at looking at your photos, your house is VERY similar to mine-would like to talk more!