That’s a very useful website. I was given a somewhat rusty and knackered Colnago which I told was a Superissimo but I had no way of confirming it. I had it restored and it’s quite nice now but I was never sure of what it was but the website confirms it is indeed a Superissimo.
Might be of some use.
http://www.cycling-obsession.com/how-to-identify-a-colnago-vintage-bike/