I'm looking to replace the Kinesis Crosslight (ugh) aluminum fork that came on my Nobilette cross bike. I don't have the original steel fork, but the bike handles nicely with the Al fork, so I'll probably go with the same geometry. I haven't measured the dimensions yet, but I'm quite certain they're will within the "normal" range.
I asked Marinoni to build a 1" cyclocross fork for me, which they are willing to do. The catch is that they no longer have the blades for 1" cross forks, so I'll have to supply my own. Back when they built full steel framesets, their most common style of cross fork was a brazed unicrown, but I doubt I'll be able to find fork blades for one of those. So I'm leaning towards sending them a full set of fork parts - steerer, crown, legs, dropouts, and maybe canti posts.
-Clearance for muddy 35mm tires. Depending on the crown clearance, I may ask them to add an under-crown fender mount and mid-blade bosses for a front lowrider rack so that the bike can double as a tourer.
-1" steerer - threaded or aheadset. The current setup is threaded, but I'm not averse to switching it up.
-reasonably light. I weigh 135#, so maximum stiffness would actually be a negative.