22 Super Shot Sealed Eight

Bentonville, what you're describing is an Iver Johnson Supershot Sealed 8 revolver made from about 1931-1957. This is an 8-shot revolver chambered in .22 LR with a break-open action, 6" barrel w/adj. rear sight, blued finish and wood grips. In excellent condition it might be worth about $200-$250. Hope this helps!

Steve

The thing that looks like a little latch behind the trigger is part of the patented "Hammer The Hammer" safety system. When the trigger is pulled all the way back, it pushes up a steel bar to transfer the blow of the hammer to the firing pin in the frame. Unless the trigger pushes up the transfer bar, the hammer rests against the frame, and can't touch the firing pin, meaning the gun won't go off accidentally if it's dropped, or the hammer gets hit by something.
EDIT: I double checked mine, and that's actually the sear that releases the hammer. The transfer bar is actually fastened to the hammer itself.

If it doesn't spell out "Iver Johnson" on the top of the barrel rib, it may just have an abbreviation like "I.J.A.&C.", for Iver Johnson Arms & Cycle Co.