...Purely speculative and to further my curiosity/knowledge, as I don't plan on doing it to my car, but will the taillight surround from a 2+2 (with the two little fake vents) interchange with a two seater?

Always thought it was an interesting look at any rate... Only recently discovered that it was stock to 2+2s rather than aftermarket

I think it should. The 2+2 was longer than the 2 seater but I don't think it was wider.

The parts manual for Australian cars shows different part numbers for all three sections of the rear finisher panel although I cannot say what the difference is beyond that which is visually obvious.

The Haynes manual shows a 0.8" or 2 centimetre difference between the two seater and 2+2 models and if I remember correctly, an earlier discussion where this was raised received clarification that the panels at the front were the same and that the difference in width was in the rear panels - sorry that I do not know if this affects the rear panel finishers.

Maybe someone else has tried to interchange these parts?