I know that the threads on old school forks ended up pretty bad back in the 80s, so picking up forks 25 years later after numerous owners poor adjustment and abuse they can be almost unusable. After a bit of investigation on cycle tools have discovered that Park tools do thread dies for 1" forks but these are mega bucks (£200). So i've been trying to hunt down a slightly cheaper alternative, and finally did it the other day.
For those that are in need of fork thread dies, old school forks are generally 1"x24 tpi BSC (British standard cycle) thread.
These people have dies in stock, carbon steel for £25 delivered or HSS (High speed steel) for about £40.
Got myself a carbon steel one the other day and its perfect for cleaning up abused old threads, delivered next day too
http://www.tracytools.com/