Walt- The Guerciotti's with the world flag logo's were pre 1984 or so and therefore pre SLX tubing. At 54cm its a sure bet its SL - 59 or so and above are more likely SP.
The custom bicycle book gives a nice history of these bikes - I've always liked 'em, mainly because my first real racing bike was one a '77 model I picked up used from a local racer when I was about 16. It was also the first bike I repainted - did it with the more modern decal set, which at the time I liked because newer is better right ;) - funny how I even liked the new cinelli logo at the time now that I think of it.
These are nice italian bikes in the showy tradition of milanese tradition. Lugs are pinned - Mondonico was a partner (or something) and alot of his influence is in these bikes.
BTW, 54-56cm is my size, hint, hint!
Alan Cline CoMotion Cycles 4765 Pacific Ave. Eugene, OR 97402
(541)342-4583 FAX 342-2210 http://www.co-motion.com mailto:email@example.com