I disagree a bit with @rccardr, having owned a pair of PDG Series 7's. They are nice, really nicely done. The lug work filing is as good as that on the Schwinn Paramount by Waterford (which I also have, right now). The unicrown fork is not popular, but that is a very nice fork, and is Tange Prestige per the Tange rep I spoke with at NAHBS. Not sure if that even makes a difference on a fork, but it's there.

I do agree that the PDG Series 7 is not, in the market, a special bike in any way. The prissy Paramount purists poo-poo anything not in their little world, and generally even each other's Paramounts, regardless of their provenance. Every bike show I've been to with a large contingent of Paramounts has no shortage of owners who are glad to show you the defects on the Paramounts that belong to others.

I doubt the OS tubing is noticeably different between the two, or the lugwork, or the weight and balance of the frame. However, one is made (gasp) in Japan, and the other in Waterford, WI. One has a lugged fork and the other has the aforementioned unicrown, which very well could be a better fork, but ugly in the eyes of the lugged world.

The main difference is the locale of manufacture, and the decals. The paint is probably better on the Series 7, as far as quality, and the Series Paramounts suffered from huge decals that mar up easily, with little remedy. Likewise, the lettering on the '91 is susceptible to damage, even from masking tape.

Obviously, if the white '91 fits, you should build it and ride it, and given the size differences, the '92 does not. If you want to run 6400 "tricolor" on your '91, I see no reason not to. I don't think it begs Campagnolo, but a nice frame like that should simply have a nice group on it, and be ridden.

That '92 looks like it's an effective 53cm, more or less. I'd not mind having it. I already have the 8-sp "tricolor" group sitting here. And this, which
now is running the full 7700 group, with the mid-cage 7700GS RD and a 7700 crankset instead of the Campy you see pictured here.