Caldina Conversion GT to GTT

Hi there, I bought a 2000 GT 2wd auto St210 as an insurance write off. Had been stolen and front end removed etc. I had to go through re vin and collect all the parts from wreckers etc. Its now on the road. Now the problem, before it was stolen the prevoius owner had swapped the beams motor for the 3sgte GTT motor. They had also swapped the loom and computer. That goes beautifully but there is an incompatability between the loom of the GTT motor and the GT auto gearbox loom. Driving it as a manual it basically works but drive is in "get home" mode so no kick down etc. I suspect all you experts will say can't be done but unless I want to spend a lot of money going to manual I have to get it to work. The plug between the GTT motor loom and GT auto loom is the same but the number of wires and positions are different. Don't need tiptronic just need the "drive" instruction to work. Where can I get wiring diagrams or does anyone know the answer. If you have the answer you can have a drive of my Caldina V1 the only twin engined 3.3litre 4WD, 4WS Caldina in the world. thanks