[Transamric]

OK, here's the deal. Need you guys opinions on which code Rally's my '71 TA should have.
Background,... bought this car from the second owner in 1984, with about 81K miles. It's a Van Nuys 05A built May 7th. The 4 original road wheels were long gone, but it has its' original Rally & F60 Polyglas in the trunk, never used. 2nd owner said that spare was in the trunk when he bought it about '77. But the near mint Build Sheet, in Box 59 shows wheel code JW. The perfect spare is a KN dated M1 over 0 (zero), and 7-28.
What do I put on the 4 corners? JW's or KN's. Or, like a couple other '71 TA's I've seen, could this car have been built with both JW & KN's?
Last Q. Has anyone been able to determine at what point Pontiac switched from JW's to KN's? And why, when they appear to be identical wheels?