The hardest job on that may be removing the BB from the shell. Happened to me on my old beater frame so I had to buy a new frame ($120 from ebay). No amount of long spanners, anti-sieze, vice work would get it free.

Eventually I'll get a frame builder to replace the shell. I digress...

Check this out first would be my advice - this bike is in similar condition to my old one (before I started work on it).