There's some faint writing on the plate. I believe that is once said Barnett.
It came mounted in the frame as shown. I took it out/off of the frame and tried to cock it. It wasn't easily going back. So, my next thoughts are to disassemble it. Remove any old oils as they're varnish now. Oil it up and reassemble it.
Unfortunately, my mainspring clamp doesn't fit on the spring. It's way too large. So, for now it's back on the board.