I agree that the revolver looks like a toy, and that the musket looks legit although I think the hammer is likely a later replacement rather than what was put on it during the percussion conversion.
I love museums, but likewise find that mistakes are pretty common. It's not just the small ones either, I can think of false information in one display that I see every time I visit the Smithsonian in DC.
I have also found that it doesn't seem to do any good to point out their errors to them. I guess I can understand that, you are simply an outsider while whoever did the display is somebody that is actually there. Better to annoy you, the visitor, than the guy that comes in to help. Anything, in any museum, should be taken with a grain of salt.