I have a 1" threadless on my ''92 Serotta T-Max. I am running a late 90's Marzocchi Z3 but as mentioned above any 90's Marzocchi with a bolt on steerer will work. My late 90's Z3 is 70mm, a Z2 is typically 80mm.

If you can find an RST 1" threadless steerer with shim, it will work in any Marzocchi fork with a bolt on steerer. Both a 1-1/8" and 1" with a shim will fit. RST 1" steerers were readily available 4/5 years ago, but I'm not sure of the current status.

Old oil bath Marzocchi forks were pretty cheap a few years, but they seem to have gone up some. I found mine on eBay. A good one is bulletproof, a little heavy, but they ride really nice for their era.

John