I assume you're refering to non-turbo UK cars, you've got pretty much most of it there already.
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Rev 3
- no airbags, sand blasted 5 spoke alloys, orange front indicator lenses
Rev 4
- driver's airbag, diamond cut and lacquered alloys
(polished look), clear front indicator lenses
Rev 5
- driver's airbag painted thinner 5 spoke alloys, combat spoiler, red stitched gear knob, red instrument panel lights, front indicator lenses
Pretty sure you're right about the T-bars always having leather seats, doesn't mean sunroof/tintop models won't though.
Bear in mind optional extras will mean some may have passenger airbags, folding wing mirrors, cruise control etc, oh and an ejector seat
Engine's have small differences rev 3 to rev4/5 but nothing too major and almost the same power I think.
Sure I've missed a few things.
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