No I'll persevere for now - after pricing everything, I can still possibly do it all (or get it done) within a reasonable budget. Will get some quotes for things this week so I can save/budget.
The AC I am calling at worst a dud compressor which would be maybe $750 to replace. The clutch isn't even working, it should be cycling on and off and it isn't. But, it could be something simple as a broken wire, dud switch or solenoid.
Paint I'm calling 5 panels (3 down the side, front spoiler and rear bar) maybe $2k. Paint on horizontal surfaces is weathered but should polish up well (tried a few small sections). The paint that is flaking off is the new paint over the original finish. More or less the same colour, at least they got the colour match good!
Seat bolster I'll give to the local auto upholsterer - the fabric is still 100%. Maybe $150-200.
3 door dings down the side that I am not painting maybe $200 tops for PDR.
The diff is caked in oil so hopefully its just an oil leak with insufficient fluid. If I put an oil seal on it, fill it with oil maybe with some oil stabiliser that'll sort the diff out - hopefully.
Car performed strongly on the trip home, returning 8.7L/100km between Yass and Orange. A couple of times between Canowindra and Orange it had to shift into 3rd gear lol.