Yep I'm sorry to hear this, but you have run into the Swift forks problem. This has stymied me since the beginning. I have not been able to source a fork with correct crown-to-dropout dimension. Will that fork you have take the 451 wheels? I suspect perhaps not.

If you do fit this fork, I would suggest that you use a clamp to get the headset preload correct, and then just fit the Joey riser over the steerer tube. There is a headset from DiaCompe which has such a clamp. The function of the clamp is such that in a normal Aheadset fork, the stem can be removed without affecting the headset preload.

You may opt to get another Joey riser and take it to a machinist shop to very slightly enlarge the inner diameter such that it fits the steerer tube. That will still leave you with the original riser should you wish to swap back.

[edit]:

Alternatively, an aluminium tube of the correct inner diameter to slip over the steerer tube would serve as a long spacer would work with a normal Aheadset fork setup. I have done this on my R20.

I wouldn't go with a short fork for the simple reason I wouldn't like the looks of the sloping down top tube.