Thanks so much, all three of you. Every once and a while, I am reminded why the internet can be worth while.

T-Mar, the knurls on the steer tube you describe are exactly what I saw when I had the bike apart. I'll keep that 25.7 mm measurement in mind and check out the headsets cuda2k reccomends. Failing that, divineAndbright, I might have to take you up on that offer. The fork crown race is really the only seriously damaged peice of the headset, so if I deal with this problem now, this bike may well last another 30-40 years.

Thanks again, e-pals, I'll let you know how it all turns out.