I think you might have a hard time finding a fork in the geometry you need, with mid-fork braze-ons, for a decent price, or not custom made. IIRC you are looking for either a 440mm or a 425mm fork. 413mm is likely to be squirrelly unless your original fork was a 60mm travel one. Possibly even then. Do you know what model fork was originally on it? Assuming it was a shock fork, we should be able to determine what size replacement rigid fork you need from what it originally had.

If you are willing to forego the mid-fork braze-ons, there are some options out there in the sizes you need. I replaced the Rockshox Judy 21R on my girlfriends 1996 GT Pantera with an IRD 440mm fork and it worked perfectly. Handles great, she uses it around town (10, 20 and 35 mile rides) and for unloaded touring to bed and breakfasts. She loves that bike now. At the time (two years ago?) IIRC, I shelled out $115 (shipped) for it. I'm having a hard time finding them online, but one search redirects to Soma's 440mm "rigid fork for cantilevers" which appears to be exactly it. Same black glossy color and yellow Tange steel logo. Looks like these are going for $125 plus shipping now, although a LBS might be able to get it in for less, or at least spare you the shipping expense.
http://store.somafab.com/socrmtbfoca.html

I'd second the vote for either going with Old Man Mountain racks so you don't need to use mid-fork braze-ons or using P-clamps to make other racks work. I've used both very successfully. The only downside of OMM racks I can see, is your bike won't fit in a roof top bike rack that requires the front fork to fit into it (the attachment at the fork bulks it up so it won't fit). OMM racks otherwise have a great reputation, deservedly so, as they are bombproof. I've taken mine far beyond what it was designed for and it handled it like a champ.

I was leery of P-clamps at first, but I attached my Nitto Big Front Rack to an MTB fork with them and have had zero issues in the nearly three years since I mounted it. That's with running heavy asymmetrical loads regularly, very regularly having a heavy load on the top of the rack, riding daily over rough roads, and having loaded it pretty heavily for a couple of short tours, including one with a fairly lengthy very rough gravel segment. I once filled a full sized Ortlieb pannier to overflowing with donated books, hung it on one side of the rack and hauled it the ~8 miles home over quite rough roads, and still it didn't show any signs of slipping or the clamp failing.

The P-clamps that came with the Nitto Big Front Rack were actually too small to wrap around my fat MTB forks (another old GT) and so I used them as a model, bought a scrap of aluminum sheet stock from a hardware store and used tin snips to fashion my own. IIRC, the rubber cushions that came with it to put between the clamp and the fork ended up being too short as well and I simply fashioned similar replacements out of an old inner tube. Still going strong, with no signs of slipping or fracturing nearly three hard years over rough roads later.


FWIW, at the time I replaced my girlfriends shock fork, I did some research and came up with:
(quoting myself from my notes at the time)

Kona Project 2: 60-70$, ugly?, eyelets, crown hole, 440mm, 1040g/813g (disc vs canti weight, triple butted)
disc tabbed http://www.cycle-solutions.com/Project-2-26-P4797.aspx
http://www.cambriabike.com/shopexd.asp?ID=87429
http://www.bikeman.com/KON-P2MTN440.html

96$ IRD 440, 40mm rake, black, unicrown, 907g, eyelets,
http://www.speedgoat.com/Catalog.asp...116&Prod=22806

$103 for Soma, canti, 40mm rake, 440mm length,
http://www.niagaracycle.com/product_...ucts_id=802955
http://store.somafab.com/socrmtbfoca.html

One One Inbred fork is 440mm.
Van Nicholas VNT TRX Alloy MTB Fork is only 420mm
IndyFab no-Travel fork is 430mm for 80mm fork replacement.

Vicious Cycles (custom) forks are very expensive i.e. $275 + $15 for fender tabs + $60 for low rider rack mounts. Straight blade.


At the end of my notes is also this unattributed quote I snatched from somewhere on the web: "Kona and Surly forks are too short at 410mm, unless you want crazy twitchy handling. Vicious and Salsa are the only two currently available that (I know of that) are the correct length 425mm (or so)." I believe this was from a thread somewhere (MTBR forums maybe, if not, likely here at Bikeforums) specifically addressing Rockshox Judy 21R replacement, or 80mm travel fork replacement.

That's the extent of my notes from then, although I did come across several other places online that do custom forks, I just neglected to jot any info down, as they were rather pricey and had decided to forego mid-fork mounts at that point. If you have the dough, there are a number of places out there that will custom make forks for you, but you'll have to come up with some measurements for them to work from or make an educated guess from some options they might have.


FWIW, at first I was afraid that what I really needed was a closer to a 425mm fork from the measurements I had taken. I went ahead and went with a 440 because the bike was a little sporty to begin with and a figured if it was just a touch high that would tame it just a bit. I don't know if my inexpert measurements were off, or my rationale was dead on, but the bike handles fantastically for her, she really loves it.


Hope that helps!