well the seatstay caps are different, but that might just be a case of "stay cap de jure". I think you have a '86 Squadra frame that at some point had 600 installed on it. now the Squadra, Brava, Limited and Nouvo Alloro all shared the same frame that year. it could be as I said previously it was done in the shop to accomidate a customer's size or color. it sould have been done at the factory, they needed to build 30 52cm limiteds but only 52cm Squadra frames were available. it could have been bought as a Squadra and the original or subsequent owners changed the parts. at a shop I worked in we had a real nice '85 Vittoria with all Victory but we could not sell it until we put 600 derailleurs and shifters on it.

if this bike fits (is that stem too high?) and is in rideable condition I think you got a great deal for 250. it is likely top dollar for that bike but if you bought it to ride it great deal. thos Formula 2 Superset frames were real nice. I believe the tubes were somewhere between a Alle and SL quality, so it should be an awsome ride. congrats on a great ride!