[quote name=\'Jimmy Owen\' date=\'Jul 20 2003, 09:23 PM\']Probably because the gentlemen were no longer working for the respective companies when their names were dropped.[/quote]
If memory serves, Bill Todman passed away in (I think) 1979. The decision was made to rename the company at that point (I'm not exactly sure why, but many of the shows in production at that time [CS, P+, FF, TPIR] opted to keep the G/T name--although TPIR and FF eventually moved on to MGP).
In the case of HQ, Quigley retired from HQ either during or after the production of LVG. Heatter carried on the production company using his own name with the creation of BATTLESTARS. Dixon Hayes' site indicates that Quigley died in 1989.
Doug