['ol Pinion head]

Love the color combo, highly doubt it began life as a M22 car...

6 areas of interest on this one... several of those points have been mentioned before.

1) factory AC charged on invoice copy, yet body build w no AC....
those of us that have been around a long time know of some very collectible 64-65 GTO's & later Dport RA GTO's that had factory AC added by owners. Fairly common in the mid to late 80's & know I'm not not the only vendor that provided AC system changeovers. On all of those legal swaps, the conversions were done by cutting out the face of the original cowl, along with bodywork.. Similar deals have been performed on numerous factory AC cars that an owner modified the face of the cowl to accept a factory heater setup. Where's this lead on any highly collectible auction car = Disclosue. What's going on should be noted, otherwise, the outer box needs to be removed & conf VIN noted.

2) VIN to body number span... 2N505476 fits in the 09D Norwood body build range, not 01B as noted on the auction cars trim tag. Why such a deal, read further. look closer at the pic of the trim tag, then look at the pic of several original '72 Firebird trim tags, easy to spot what's going on...

3) stamping of partial vin on the block, nuff said...

4) engine assembly number of ( 228159 does not fit for an early to late Fall of 71 WM engine build.

5) interestingly, the invoice copy notes ZS1 17-1535 & 9D at the bottom of the option lists.
also notes a 5 PCT car, this coincides with the 1/31/1972 ship date. Def some form of "Brasshat".

6) prev auction listings of near a decade ago noted this N505xxx T/A as a project with some concern.