Topic has drifted, but...
More GTs than GTVs? ....well, the simple explanation was surely that the production run was longer, 3ish years GT versus 2ish GTV, no? So @ 7,000 p.a. sales for each model. Not really a popularity differential, then.
GTV 3hp increase only? Yes, but ‘significantly more torque’ was the quote I remember from way back then: smaller inlet ports getting the credit, IIRC, which was kind of a surprise to the bigger-ports-are-better guys. What I didn’t see reported anywhere were the comparative torque numbers.
Having owned both cars, I don't remember interior differences other than the fake-wood dash veneer (which I don’t like) chrome dash trim, under-dash light, a redline on the tach, seats, arm rests, and sun visor and grab-handle colours. Not really much ‘better’, really. I’d say the GT seats were more comfortable, but GTV had better location with the side bolsters.
Steve105, that’s a bit of a long bow you‘re drawing re the wheel arch changes. If you don’t mind me borrowing your bow for a sec, I reckon it was a racing-related thing, maybe for fatter wheels/tyres.