I was wondering if the 31-03 was the same transfer box with a different flange but the 31-01 was a unit offered by BW that Tesla brought the entire production and rights to so BW cannot even sell you parts if they wanted to. I would love to see the 2 together. If you need new gears cut PM me as I used to cut them for Prodrive back when I lived in the UK. I may still be able to find someone who can still do it.