Looks like somebody took a can of krylon to it. What patent dates are visible? There should be text on the barrel rib though the "refinish" might have obscured it.
edit: I just noticed something very strange too. What's with the latch? Normally that's secured with a flat head screw which should be visible on the left side of the frame. It looks like yours has a pin there instead. Is that a camera trick or is that a pin holding the latch on?
If it's a pin, someone probably stretched the original latch screw shooting smokeless loads, and fixed it by drilling the hole wider and using a larger diameter pin to hold the latch.