Well after some serious thought and a little bit of both good and bad luck I decided to switch to plan B on this upcoming project. I managed to find 2 things while out looking for parts. Plan B involves about 10 times less fab work than the original plan and is alot easier to obtain. I will not mention Plan B or post the actual project until it's completed so there won't be any debate about it. The original plan was to use an old 1983 Ranger cab that I found that needs minimum work. That part has not changed. The engine and tranny choice has. I managed to find an actual "P-51 Mustang Aircraft Merlin engine and transmission". I got extremely lucky on this one, but soon ran into bad luck shortly afterwards. After looking at it and the old ranger that I found, I realized it wouldn't work no matter what I did, including just buying the cab and building a tube chassis around it to get the merlin engine and tranny to fit. The guy said he'd hold both of them for me and would give me the engine for free since it seized up and would require alot of work to get running, but I would have to buy the tranny since it was just rebuilt. I went today after the carshow to let him know that he could keep it, but he'd already sold it. Someone had made him an offer he couldn't refuse which does happen from time to time. The original drivetrain choice I had was just too unrealistic to say the least.
Here's an old photo of the ranger I found which is still there today: