Older fork meets younger headset....is the age gap too much? (Compatibility question)

Hello,

1. The crown race doesn't seem like it'll fit. I've installed a good few before, I know it involves liberal use of a hammer, but this one wouldn't seem to budge at all.
   
   
   
   
   
   

The crown race seat can vary in size, I think some are 27mm and some are 26.5mm.

I had this problem with a modern fork and a Campag record headset. I took it into a bike shop, and they milled it down free of charge (Cycle Surgery West hampstead)

Not sure about the thread question, but Sheldon has a good bit on fork/headset compatibility.

http://www.sheldonbrown.com/cribsheet-headsets.html