Aaron-
Did you find some locally?
Search the Rust archives or other parts of the board for learning everyone's favorite method for getting 50 year-old rusty bolts to budge. I recommend PB Blaster rather than WD-40 before heat. Also, applying some force forward (tightening) before applying oil/blaster then removal seems to be a good mode. If you got a Stovebolt, you've spent time trying to coax these apart before they snap.
Good luck!