Check with Robinson's. He has a great web site and tons of knobs etc. He will know where you can get them I bet.

Here is a link that might be useful: hardware

I just noticed these in a catalog that I had laying around. Sounds like what you are looking for?

Here is a link that might be useful: Rocky Mountain K150

Renovator's Supply has a selection of glass knobs, not sure if any are egg shaped.

Thanks everyone. They are very similar to the Rocky Mountain knobs, though I'd love to find a vintage source. I didn't see anything at Renovator's that matched, but I'll do some more searching with Robinson's as well. Thanks!

Many of the antique stores downtown have bins filled with old latches, doorknobs, and other hardware. Have you ever just tried looking in places like that? I'm not sure about the age of glass knobs, remember seeing a lot of them in older houses when I was a kid.......my old house has what looks like white porcelain knobs on the exterior doors, and latches on what interior doors had hardware at all.

From what I've read, glass knobs have been around since the mid 1800s, but they became really popular around WWI when the metals were being used to make ammunition and such. I'll need to take a bit of a "field trip" to check out some of the salvage yards around - most of our antique stores locally deal with lovely (but expensive) antique furniture rather than (what I would consider) the more "fun" stuff like hardware. We live in an old victorian house now, so I'm pretty used to the glass knobs, but the vast majority are faceted and hexagonal (or octagonal) rather than oval and smooth. I haven't seen ones like these before and was curious if others have. I like the porcelain knobs as well - you are lucky to have them!