Welcome... fellow All-Trac / 4WD / Carib Sprinter owner! Is your model a right-hand drive, or left-hand drive? You have the front bumper that I love so much. And side markers...
You could try another forum (which I can't mention here, but can send you a PM) to buy a used loom. Do you have a partial loom? Like the connectors that are on the engine and some of the wiring, but not all the way through the firewall? If so, you may be able to extend the wires and run them to the ECU (computer). By the way, you will need the 4A-GE ECU. This can also be bought from someone on a forum.
What year is the 4A-GE? Is it bigport (T-VIS equipped) or smallport? Also a bit of advice, while you can fit the GE into that AE95, you will need to grind away some of the block & oil pan to clear the transfer case. There's a lot more info about swapping a 4A-GE into an AE95, but I think I've typed enough for one post