[MENTION=41044]Gary Fountain[/MENTION].

Thx for your reply, the reason I guessed it was 80is because of the small tube between the chain stays is still a tube. According to some timeline tables from 81 the chain stay bridge had more like a spool shape + colnago stamped on the sides of chain stay..
But again not an expert, just what I found on the internet from my own research.

I will try to take some more pictures of the clean bike tonight.
The pics I made in album is when I just got the bike (very dirty)

Anyone has an idea about the number 'H36' on the bottom bracket? -- as I think it has not been replaced, but could be wrong also.