I am no expert (or even novice) regarding the OP's profession or S & W memorabilia, but a I-net search of "early Smith & Wesson trademark symbols" didn't run up much, but further scrounging around pulled up a "Soft Beer" presentation S&W gun dated 1905 and the stock medallions sure look like symmetrical diamonds (equally tall as wide), so maybe the catalogs, paper goods, price lists, dealer info was just the way particular artists made their "rendition" of the "stylized diamonds".
Hope the image uploads...if not...trust me
Beats me, maybe the OP's brass (bronze) is off of a belt buckle. There is an item on E-bay right now (cannot post link...against forum rules) that appears to be a small keg with a brass medallion embedded in the side and is shown a little larger than a quarter photoed next to it. Since a quarter is about 15/16" diameter and 30 mm = 1-3/16" I would say maybe an aftermarket thing or dealer/distributor hand out. There is also a elk horn belt buckle for sale with looks like the same bronze medallion and it also looks like about 1-? inch diameter and the belt buckle is 2-1/4" high so who knows.
I remember in the 80's that you could get anything with S & W trademark logos, from belt buckles, Zippos, hitch covers, floormats, jackets, shooting patches, key fobs/chains, etc. on and on.
How one that old got under the earth in the Ukraine is way beyond my pay grade.