Sideplate screws with buggered heads would also indicate tinkering of the 'Bubba' nature, along with a peeled or lipped edge on the sideplate.
It's not unusual for the front sideplate screw (yoke) to be marked ,as many folks remove this screw when taking out the cylinder/yoke assembly for cleaning.
Also bear in mind; many bores, especially at pawn shops, may look shot out or excessively worn when in fact it's a leaded bore that only needs cleaning....guns don't always get cleaned before going on display.
...Then I found a place it's dark and it's rotted
it's a cool, sweet kinda-place where the copters won't spot it.