1976 chevy bonanza 4wd shift position

[montesa]

Hello

I have a 1976 Chevy Bonanza short bed 4wd auto trans with a what looks like an NP203 transfer case from the outside but the shift position is forward for high and back for low with only two positions. I know all NP203s are 4 position with high being back so looking to see if anyone knows anything about this issue. I got this truck from my brother whom passed away and know through telephone conversations the issues with the truck. From what he claimed was this truck is some type of prototype and GM lost a patent issue with Land Rover which is why they never produced this transfer case. I recently spoke to a person with a 70s land rover and sure enough high is forward and low is back with only two positions. When I insured the truck the insurance company questioned the vin number claiming it comes out as a Chevy Laguna and I had to bring in the original tag in the glove compartment to prove the vin number is real by the weathering. Does anyone know or heard of an NP203 that is setup this way? only two positions with high being forward or know anything about 1976 Chevy prototype? He had claimed there were two made while the other one was crashed and burned and this is the only one left? It looks like there is some type of what looks like heavy gauge wiring which is enclosed in metal tube which runs to back of truck where it looks like something was cut off the rear of the frame. The heavy gauge wiring goes to the alternator where it looks like someone spliced in a standard alternator with regular wiring. He had told me everything in this truck is old style where the density of the cast iron is different?
Appreciate any help