Seems like you got it.....Just to check I put a magnet on it and they are steel under the copper.I have a few remaining from hundreds I bought back in the early 1990's for use in CAS in a double barrel 12 ga. The cases are steel with a copper wash and are in fact Russian in origin. The ones I have left have the identical head stamp. I bet the 92 is the manufactured date. Mine have a "3" on the plastic top wad, which is the shot size. I had to reload with smaller shot to meet CAS/SASS requirements. These were fun to shoot, somewhat more "authentic" in matches than plastic ammo, and got a lot of attention. Other shooters wanted to keep the empties, which was okay with me because they took, IIRC, an odd sized and perhaps Berdan primer. Definitely not US military, kiln shots, or airplane engine starters. And they are not brass.
I think it's a Coffman device, an engine starter, filed with cordite to turn over aircraft engines from the 1930's.
Probably not a good idea to put into a shotgun unless you want to tie it to a tree and pull the trigger with a stick.
Brass cased shotgun shells are not uncommon in the world of Cowboy Action Shooting, in fact they became so much in demand for those shooting in the black powder classification that they were brought back from obscurity, and Magtech is now making them to SASS specifications in all popular gauges.
What do those shells measure out to for OAL? They look long for standard 12 gauge.
The first thing that came to mind on the head stamp was Kynoch... but doubtful.
Difficult to determine what they might be given the widespread sporting and industrial use of 12 gauge loadings. You might need to open one up to see if has shot or is power only, which would clearly be a non-sporting application.