As a follow-up, I opted to have the mast welded, since I had an upcoming trip and didn't have time to find a replacement mast. It cost $80 (1 hour labor, with travel, I believe) to have done, and while it doesn't look pretty, for a 30+ year old boat, it seems to be good enough. You can see the repaired pic at the end of the album I posted:
http://imgur.com/a/Zu9wp#gTc4eqoI'm sure it's not as good as new, but I imagine that it will probably get me at least a few more years of sailing out of the mast.