A lot of hunting online helped me find a couple of .38 cal. rimfire "Robin Hood" revolvers, just like the one which I bought back in August.
The Hood F.A. Company may have made two or three variations of the .38 cal. Revolver Patented April 6,1875.
One was the "Robin Hood No.4", which didn't have a removable side plate, and another was branded with the company name, and had a removable side plate.
I found another model without the side plate which was branded "Alaska 30".
There are all nickel plated, single action big bore pocket revolvers chambered for the .38 cal. Rimfire cartridge.
The .38 cal. Rimfire cartridge was a reasonably potent self defense round at the time these were manufactured.