two battery wiring starter

The two batteries should be wired in parallel so you still only have twelve volts. The starter is a twelve volt unit so there is no special wiring involved. Basically you have the same wiring as a single battery, just two connections for each instead of one.

I cannot find a good schematic of it as it was not sold in the US as a diesel just a gas model.

Both of the twelve volt batteries are ground to the car body. question is where do the two positive leads go for the starter motor? thank you.

They both connect to the twelve volt positive terminal on the starter solenoid. Then there should be another cable from that to the main fuse box feed.