Those Spicer forks do not look so good up close. Also, I think they have a fairly substantial amount of rake to them... Yojimbo's in Chicago has the threaded cinelli forks in stock. Far more expensive, but a much nicer fork. Heck, Yellow Jersey has 3rensho forks...

If you're dead set on the idea, you'd be better served to take the thing to a frame builder and get an entirely new steerer brazed on. I believe that Mikkelson has done this for a few people on the forum for around $40.

However, for the time and/or effort you're going to put into this, you could probably get someone like Johnny Coast or Moyer or any other less-established frame builder to make you a fork. The spicer fork is what, $100? Add another $20-50 to get the thing threaded and then you're at the point where for another $50 or so you could get something custom.