I do not think the Competizione frames are much different, maybe Columbus SP instead of SL, but I think a lot of the Specialissima's were a mix, or all SP sometimes. I know mine weighs as much as an SP frame.

They were pretty much indentically specd. as well except for the Magistroni steel crank in place of the cotterless alloy Record. Italia saddle instead of a Brooks Comp Standard. If that bike is available and reasonably priced I would grab it. I doubt anybody could tell the difference between riding a similar year Competizione and Specialissima in a blindfold test (if you could actually ride in a blindfold).

The lower end bike from that period is the Gran Sport. That one is noticeably a lesser bike. Stamped drop-outs, etc. But similar livery so hard to tell from your not too detailed pics.