I made a 12H-T swap on my Bj75, it is technically identical to the Bj70. These links may be useful to you (please use a translator Finnish => English :))
Offipalsta.COM - Näytä yksittäinen viesti - BJ75 SA-1084 -...
I found used 12 volt LJ78 amplifier and this BJ75 is 24 V, so I had to add a couple of 24 volt relays to get the ac control working properly. The troopy has also 12 volt system for camper use, which I used to power the amplifier.
After pressure...
Finally I have working ac in my troopy. Had to look for parts from many source, but hardest part was probably the hoses and specially fittings. I wanted to use Toyota's original cooler unit, amplifier and dashboard controls. Compressor, codenser...