Obviously, you must be a lawyer who handles these types of cases to speak with such authority?
I certainly wouldn't argue that TSR's financial records at the date of purchase did not become the property of WotC, but unless WotC stipulated certain data be present, there is no certainty that it would be part of TSR's records at that time.
In another thread, Mr. Gygax mentioned things he was working on that he removed from his desk prior to being ousted by TSR, which were not specifically purchased by TSR.
Are you actually saying that you believe that it is unlikely that TSR shredded or removed non-critical documentation prior to sale and transfer? Despite knowing that the previous transfer of ownership (from Gygax) was accompanied by similar behavior? If so, your understanding of human nature is radically different than my own.
RC