After reading through the complete Guerciotti Jet thread again:

1. Angles will always vary by frame size and jig setup. There are/were various cycling federation specifications for the wheelbase and allowed lengths of the various parts of the frameset-- catalogs are almost-never right with this. This was my big "surprise," when I first got out my angle finders and measured my frameset.

2. My Guerciotti Jet also has a chromed cinelli CC fork crown, with brazed-on tabs with star-shaped cutouts. All dropouts are chromed and are masked off. The right side chainstay of my Jet is masked off. The masking line is "scalloped," but there is no pinstriping at the masking line on the stay. There are some shaky yellow pinstripes, where the seatstays join the rear dropouts.

3. Guerciotti track framesets from this era generally featured fully-chromed forks, with semi-sloping fork crowns (Actually the road forks were fully-chromed, but only the crown and dropouts were polished, so the blades were painted).

4. The Pista framesets often featured bulge-formed and welded bottom bracket shells, with a large star cutout. Road framesets of the era featured Cinelli CCM Bottom Bracket shells, in italian threading.

5. Columbus SLX and SPX did not come onto the market until 1984, or so. As I understand the evolution, some builders (I don't know who) were asking Columbus to also rifle the seat tube, to strengthen it. (A road frameset fatigue failure almost-always starts at one of three points: a. on the right side of the seat tube, right where it joins the bb shell b. on the underside of the downtube, at the point of the lower head lug c. the right dropout breaks, where it joins the right chainstay). This was probably also in reaction to the additional fatigue strength needed because of the fad of adding the front derailleur braze on. Columbus then turned this into a full tubeset.

Best Regards, Mark