An interesting build that has captured my attention! I love Concorde, and of course TVT.
I think the accuracy of components will pay off in the end, and any compromises should always be small and the least visible. Things like front and rear mechs are too visible to get wrong when you've gone to so much trouble with the rest.
Without spoiling the party on what is a great build, I believe that the monoblock TVT was the last edition and built from 92 to 93. The earlier versions were used extensively by many pro teams, and the PDM ones could often be seen with painted head tube lugs too. If you carefully study some of the grainy photographs available, then you'll just about see that the head tube is flared at the top and bottom on many of them which reinforces the belief that they simply painted the alloy lugs and stuck the Concorde head badge on.
A few pro teams got in trouble for using the superior TVT frame design rather than the heavier steel frames they were sponsored to ride. The Banesto and Pinarello partnership is likely the most documented for this because they were claiming the most prestigious wins on a frame that clearly wasn't a Pinarello, and consequently forced to use a steel Pinarello to cross the line in Paris!
Another lesser known fact was that the pros would usually insist on using the higher modular carbon version. This was stamped TVT in the lugwork to identify it as being 20% stiffer, and lighter than its high resistance carbon brother. Greg LeMond and the Z team would almost always use the HM version, and it's often something overlooked by thos wishing to build replica team bikes. That said, many teams went as particular as LeMond, and a plain HR carbon TVT was way better in the mountains than any steel frame they'd been used to riding before.
What are the stampings on the BB? The year of manufacture is within the top line of markings. The bottom markings refer to size.