If you have the time and energy, absolutely read this thread:
http://thefiringline.com/forums/showthread.php?t=57816
Keep in mind that even if you can't do all of this or you don't feel comfortable with your own assessment of what you may see or feel when you have the revolver in your hands, reading this is still arming yourself with information.
It may seem like information overload. It may in fact be...info overload!
But even for someone that is fairly new to revolvers, it is helpful.
I have a few particular things that I look for when I'm inspecting a used revolver. This checklist is even more comprehensive.
Happy shopping. If you end up bringing it home, don't even think about showing it off without
pictures. 