Actually, I just wrote Mark about this, and there is some wiggle room in the timing. Pegoretti was Piniarello's contract builder from 1991 through 1997. He built a number of frames for Indurain; the measurements are in the files. Indurain's earlier years were probably TVT's (can't say I know personally). He may have had a TVT for certain uses later in his career as well, as there was plenty of cross-dressing going on. But, for the greater part of his tour-winning years, they, and all other Piniarello's, were Pegorettis.
Interestingly enough, it is precisely because of these discussions that current team suppliers have iron-clad contracts with their teams and riders. There's too much money involved for these questions. You no ride the sponsor's bike, you no ride on the team.
Charlie Shafer
Madison, Ct