Hello,
I just purchased a M997 2 weeks ago with the same issue, no rear doors. However, I was able to acquire 2 right side doors through ebay of which I deconstructed one of them and then reverse engineered a left side door using the same type aluminum, 1/4" PVC sheet, 3/4" plywood (Treated) and sandwiched together with marine grade adhesive and small bolts throughout. Total investment for one door is roughly $350. The door is much stronger than the original to which I bolted a spare tire carrier. This week I'll be building a right side door using same technique.
I am wondering if you have a follow up on the spare tire mount? Is it holding up? Are 3 hinges enough? Where did you get the mount? We are looking at an ambulance that has the doors already, and we have a mandatory requirement for a spare tire on the rig.
Thanks for any help
Dan