The screws being dinged up is a really good sign someone has been inside the gun. If you can't use the right tool to remove the sideplate screws, there is a good chance that the side plate wasn't removed correctly, and God only knows what mess they did inside.

I have bought screws from this guy for other guns that had mangled screws. I am leery of a gun with mangled screws but will still buy if I can get a deal and there is no push off.

Smith & Wesson K L N Frame Revolver Side Plate Screw Set - Stainless Steel - The Gun Garage