I cleaned up a nasty bar on the super 660 I'm working on. Bar #68P19. It's a hard nose bar. The chain that came off of it is oregon #51 .404 .058 the chain is froze up from rust. I tried a .063 chain on the bar and it seemed to slide fine. The old chain is 64DL and looks to have never been sharpened. Any thoughts guys? Can I soak the chain in something to free it up or once they get like that there toast?