So, maybe I can rebuild it? So I googled that. I read lots of posts of failed rebuilds using the ~$30 rebuild kit. Something about the bore becoming oblonged over the years, so most people recommended getting it resleeved ($80 for just a resleeve) plus time...
http://www.stangerssite.com/brakevalve.html
So, I really don't want to use something like that anymore.