Nice truck! The transmission shift pattern sounds like the Clark thats in my COE. It really takes some getting used to. The shift pattern looks like this:
2 5 R
I-I-I
3 4 1
It takes some un-learning to drive with that tranny. Mine is actually an overdrive, so the way to shift the two speed rear in the upper gears is 4l - 5l - 4h - 5h.
Good luck with your truck. Is sure is a cool one.
Scott