I discussed this with a friend of mine a few weeks ago, and he was in contact with a major parts resto house. It seems that the 69 Firebird radios always garner a premium because people feel they are very unique. However, my friend said that the 69 Birds use the same radio as the 69 A-bodies (maybe even all the 68-72 A-body Pontiacs, not sure), the only difference being the buttons. There is a discussion going on now about possibly reproducing the correct 69 F/B buttons.
Not only would people with original 69 F/B radios buy new buttons, but it would allow radio resto houses to use either F-body or A-body radios as donars, and simply put the F/B buttons on.