I think the question pertains to frames that will fit the shape of a vintage license plate. Sometime after the 1950's the Federal government mandated the size and shape a license plate must be for all states. Prior to that they could be any size and shape as perscribed by an individual state. I recall that the state of Tennessee had their plates in the map shape of the state.
Here in California the 1928 plates are very narrow, the later were larger, but I don't think they are the same size as modern plates.
The Bratton part numbers refer to a frame that fits a modern size plate, but with the words, "Model A, and the year.
You would almost have to find frames for vintage plates at swap meets or from collectors. You see a lot of YOM plates on Model A's in California, but I don't recall ever seeing a frame on one.
Good question, there is probably a market for them.
I have a pair of early plate frames that i aquired with a connecticut license plate collection from 1919 to the late fortys. These are three and four digit plates and are smaller than the modern plates we now have. I got these from a friend of the family about 55 yrs ago when i was a kid for doing some yard work. The frames are gold anodized and have a backing plate that keeps the plate tight and it hinges to open. They even have a plastic face plate. I have never seen another like them, but i bet a good start would be Hershey.
LeBaron Bonney sells YOM plate frames in crome which are real nice.
I believe CA and NYS were the same size then, and they fit my NYS YOM's.
LBB mentions they are for Calif.
LBB Item # B-13409 S