I finally bit the bullet and sent it to John Van Steltan in Colorado. After 5 weeks of seemingly endless waiting (but only 3 of those weeks were the actual repair time), I got it back.
I haven't this roll of film yet, but the lens looks pristine. I can see some paint loss around the perimeter of the first lens group housing (which is a metal barrel that makes removing the first lens difficult, if not impossible), but the rest of the lens is intact.
It wasn't a cheap repair, but considering how well it turned out, and given the reputation of this lens, I think it's worthwhile.