Here's what I have. It's a Tange steel fork, approx. 410-415 A-C and 185mm 1 1/8" threadless steerer.
I just measured, and this won't work for me, but thanks. It looks like I will need a minimum of 230mm for a threadless fork to get the height up high enough. I would have preferred a more 'classic' geometry frame like a Bridgestone, but I've gotta work with what I've got (and I can already see the fireworks if I took apart mom's Trek, so that isn't going to happen). If the right/cheap frame comes along, I'm not opposed to re-starting with a 1" head tube...
So, I'm going to update the first post with the following information, and leave this thread open, but eventually I'll just need to buy a [new] fork, if nothing comes along:
-Threadless 1 1/8: needs at least 230mm steerer length
-Threaded 1 1/8: needs at least 165mm, 175mm preferable
-Lugs preferable to unicrown (ha, that's a stretch), Would like 58-60mm actual space in between the legs, a little less okay.
-Doesn't need to be a mountain bike fork, as long as it is 398 axle-to-crown (or a bit more), which would almost guarantee that it is coming from a touring bike/mountain bike, anyway.
-The above can be slightly lower, if there is more offset to the fork (+45mm)
-Cantilever studs preferable to disc mounts, but I can deal if something nice comes along.