Okay, so I took 10 minutes to browse the '68 and '69 parts manuals. My part # 2649 963 isn't even there so lost on it as "2649" numbers seem to be only in the alternator section. When I restored my Bee, I removed my pioneer and put back my original "CHRYCO" radio from the parts shelf back in. At the time we had much discussion about it and the jist of it was that Chrysler Canada had some trademark or deal that '69 "ordered and sold to Canada cars" had to have CHRYCO radios in them. I know 100% this is the radio that came in my car.
Per the USA parts manuals that I got from Moparsaver.
1968 cars have different part numbers for radios, for the Belvedere and Coronet lines. Which would explain the Plymouth and Dodge faceplates in 1968 cars.
All AM radios
2884 060 = R vehicles (Belvedere/Sat/Roadrunner/GTX)
2884 062 = W vehicles (the Coronet line)
2884 064 = W vehicles and was a "deluxe" AM radio and it was only in W cars.
1969
2884 064 = W car line only and again the model 389 AM deluxe radio as above.
2884 635 = both R and W car lines and was an AM/FM radio, so I assume as R413/Scott said, probably had Chrysler on it so it worked in both car lines.
2884 634 = both R and W car lines and was the standard AM radio
2884 636 = both R and W car lines and was AM w/stereo tape