To get the 79 to a standard similar to the Gren will cost us Aussies about 20K extra for the 79, based on retail. Mate of mine has a completely rigged 79 (V8) and explored the idea of a new build for both 2024 models (Gren and 2.8 LC).
For the 79, that still leaves you without several cup holders, lack of airbags, lack of rear AC, lacking so much other stuff!!!
For the 79, you are going to sink $6-8K right off the bat, just to get the rear axle widened so it matches the front end... it is 2024 Toyota, how long you been building these skimpy rigs for now???
Sadly, he is going for the 79 still in the new config and spending the extra dollars because of long haul comfort issues in the Gren - even more 1st world picky than me.
Honestly, I would gladly go for the QM if they fixed the foot well design (i.e. start that area from scratch!), steering tilt and reach and lumbar support! Actually, I would trade in/sell and buy straight up.