got this columbian 604 at an auction for $35, works well, i got it all torn down and knocked off a little bit of the rust to see if there were any cracks. i thought there might have been a weld on back side but it turns out to just be a rough casting. the only damage i found was small chip on the slide, should be able to file it down. looks like someone used every surface of the vise as an anvil, so i'm trying to decide how far i should go with the clean up. also is it work taking out the pin and screw nut just to clean up that area?