not sure about that fork being OEM ALAN, but the DOs and seat lug point to a Colnago (Carbitubo) rebranded ALAN frame around 1988 to 1990, but...are any of the frame tubes/stays carbon fiber, or only the fork blades?
here's a link to a "how to date and ID Guide" which @SoCaled reminded me about just a day or two ago:
https://www.dcisite.be/en/artikel-info/alan-guide

on 2nd thought might be some flavor of 1990 R-30, but that could have ALU, or CF or Titanium main tubes but it's one (or 3) models that seems to have internal cable routing in the top tube