Terrific project.

I wouldn't necessarily call the fork 'incorrect'. Challenging images but if panto clover Colnago, likely is genuine. Thinking you've got the timeline correct including pushing 1980. So many of them out there and with contract builds, variables do exist.

Next are basing the date by its components. Nonsense. Not uncommon to have the original parts changed out during its use for many reasons. (Damage, crash, upgrade, vanity.) In this case, just look at the stem, brake cables, etc.. Also, the recessed brake cal's are no biggie as that's another easy or rather common change out. Go either way or back date by getting a longer stud mount and use a bushing in the fork crown.

Paint, preserve, sell, part out.... it's a hobby- do as you feel and enjoy it.