I like to try and verify cars using the SPID when available. So looking at this car's SPID:
The WE2 for 1984 signified the GN option. The L/S seats were also available only on GN cars IIRC, and that is listed on the SPID as AQ9 (articulating L/S seats). It should also be on the cowl tag as well as along with W11 (Turbo). For fun, match the VIN and the SPID. Swapping trunklids wasn't out of the question, but unlikely. I mean, if you swapped everything over from a wrecked 84...doubt it's the case, but still...as a potential buyer- check everything.
Check this out- that car has J42 too. Aluminum rear drums. Not a big deal, but kinda cool. It doesn't have G80 (limited slip). From what I understand, G80 and J42 won't be on the SPID at the same time. J41 (steel drums) were with G80 cars. J42 aluminum only came with N89 wheels as well. So J42 and N89 must both be there on an 84 SPID. It also has VD6/VD7 RPO codes, which I think all T Types had anyway- Aluminum front/rear bumper reinforcements.
Check the grille for 2 mounting hole tabs where a TType badge would mount. GN's didn't have the hole tabs.
Based on what I see in the pictures, the car checks out as a GN. But with cloning, ANYTHING is possible.