87.5 CGT parts #'s, documentation?

[Jonathan Monetti]

Because I am having a hard time confirming parts #'s, I keep having this
recurring fantasy about finding an official manual titled "The 1987.5 Audi
Coupe."

Working through ETKA, Alldata, the Bentley, (and even a Haynes and
Euroselect) it seems like official documentation directly addressing the
87.5 CGT is more or less nonexistent.  (Even the Bentley's VIN
interpretation page is a curveball).

The only places I've seen address this are Shokan and Blau, where parts that
could be in conflict are highlighted. While helpful, that's a "fishing trip"
approach.  Instead, I'm trying to cast a wider net so I can understand the
nuances of 87.5 ownership.

Does documentation (besides Huw's site) exist that makes this process
easier?  Did Audi ever publish anything on the 87.5 for the dealers? TSB's,
Training Manuals, supplements, etc?

TIA
Jonathan Monetti