Banshee, reading your post from earlier, it sounds like you and I have the same theories.
While I have the utmost respect for Jim Mattison, I'm not sure he would be able to shed any light on this subject. All he would be able to do is look through his PHS library of invoices. Jim was not connected to Pontiac Motor Division in any way back then. He worked in Chevrolet’s Fleet and Special Order Department from 1967-1972, which initiated the Central Office Production Order form (COPO cars).
Personally, I believe the current crop of researchers, using the internet and painstaking detective work, would have a better grasp on what occurred with the 69 Firebird HO/RA cars. As stated earlier, we need hard documentation, in the form of Pontiac bulletins or memos, about what happened during the 1969 model year. I know SOMEONE must have this documentation.
I believe a great deal of information has been unearthed in the past few years, with the help of the net. Hopefully, the research and knowledge that you (and others) have provided will eventually clear up this issue.