Here is an interesting one. According to seller (non-watch person questioned after sale), it came as seen from an estate drawer. Could very well be on the original leather band. There was so much corrosion "greening" on the pins and hinges, it was obvious it was unmolested for a very long time. Face is a brushed silver and face and hands show no signs of radium. May have been refinished long ago, but I highly doubt it.
Case has a pinhead sized dot of plating wear on the four upper case corners - it is a remarkably well preserved example and keeping time "straight from the sock drawer". Original dust cover and ring intact.
Curiously, there is no date stamp on the 4 adjustment 15J movement, but case bears a 1926 s/n with the common lightly stamped and slightly off center first "6".
Case exterior has no stampings, besides "GF" on either end between the lugs. Case is double hinged.
I believe this is the "Green Gold" variant of the 1926 Spartan, as offered (white or green) in 1926 ads. Last photo shows it freshly polished next to a confirmed 1936 white gold Bulova Ambassador, the color difference is pretty obvious.
Bob - I think (surely someone will confirm or deny) that green gold is a variant of yellow gold and that it was sold, not rolled. This watch appears to be the standard rhodium finish common in the 1920's. The watch featured on the left is a non-rhodium finish of white gold and therefore much brighter. I looked for the advert you referred to but didn't see it.
The watch is, I think a Spartan model.
I found the ad attached to this one calling out white or green 14K filled..
https://www.mybulova.com/watches/1926-spartan-9052
I'm pretty sure green falls between white and pale yellow based on copper and silver content. Subject watch has an odd tint when side by side w/white gold that I don't recall ever seeing before. It's impossible to get a good photo representing color (like rose); in natural light (photo above) it appears darker in tint than white and in incandescent light against a white background and tilted at an angle, it appears very pale yellow with a hint of celery. It's a mystery to me with no confirmed point of reference as to what the spectrum is for green. Maybe it is rhodium over white, that's out of my field of knowledge.........what say the panel?.
I have no other pre 1930's watches in my collection to visually compare it to.
In reply to I found the ad attached to by neetstuf-4-u
I was reading on this and take this with a grain of salt because I am just repeating what I read. That rose/pink gold is made by adding copper colored alloys that give the gold a subtle pink tint and color can intesify with age. White gold is made by adding white colored alloys and white gold that is not rhodium plated can be white with a slight yellow tint. Green gold is a mixture of pure gold and silver. Green gold is yellow with a subtle green tint. It would make sense that it would be a lighter yellow than regular 14k yellow gold. Don't know if that helps at all but thought I would share.