Armory C-H was a joint venture between Armory Firearms and C-H Tool & Die, the reloading equipment makers. The Armory C-H Single Shot was announced in the 1968 Gun Digest, illustrated with an exposed hammer. It dropped out of the catalog section by 1971 with no Testfire or other article and never illustrated except with hammer (apparently the same picture, description, and price - $179 for a complete rifle - in all three issues.
Even the hammer model was described as operating LIKE a Winchester Single Shot but with NO parts interchangeability.
I could find no other mention and no listing or picture of a hammerless version. I have seen pictures of all sorts of 19th century single shots converted to hammerless, so it would not have been a whole lot of trouble for them to get a design concept for it.
The Armory C-H predates the Jap Browning Model 78 mutation of the "Highwall" by ten years and is not related that I can tell. The original Browning - Winchester Single Shot of 1885 has no direct connection with a British Farquarson that I can tell, it is pretty much a Sharps breechblock and center hung hammer action. And advertised that way by Winchester at the time.
C-H was taken over by 4D and I don't know if there is any institutional memory of a rifle three owners and 30 years ago. Wouldn't hurt to call, they might have some old literature.