I have been looking the pictures over and I am nearly positive that this is a replacement frame. My guess is that it is a replacement for a 92 or 93 M700 due to the threaded Pepperoni fork. Prior to 92, Pepperoni forks used 1' steerer and after 93 all Pepperoni forks were threadless. March of...
Nah, it happens to all of us. I don't think I could figure out half of the new headset and bottom bracket standards which is why I am so familiar with the Park website.
Can't wait to see the progress on your new frame. My 1990 M800 is also an April mfg. date:
51804901810
Your frame is made for a 1" steerer. The 1" number refers to the OD of the steerer tube. Headsets (and tires, and bottom brackets, and every other part that has ever changing standards) can get confusing. When I get lost I find that Park Tool has a lot of useful info on their website. The...
I think it is a 1990, it was the only year with round chainstays and cantilevered dropouts. Probably a late 1990 (August +/-) with the decal on the downtube or it could be a euro spec thing. I would love to see the serial number on it.
There are kit to convert from Headshok forks to conventional forks, which is what is fitted to your bike. Post a picture of the serial number, that will help fill in the details.