I've seen a friend use something very similar to the "L" shape... Simply put, both legs of the "L" were of the same length, and on each leg, fashioned out of 2X4s, he had adjustable 'claws' if you will. Think of a large wooden L-bracket that has two wooden C-clamps attached to it! :-) The "L" bracket simply pivots on two heavy carriage bolts that are mounted at the CENTER (very important here...) of the base. The base, incidentally, should be about long enough to support the majority of each arm of the "L" in either direction. The whole assembly sounds really ornate and complicated, but
For those who don't visualize well, think of an L-bracket that has two horizontal bars attached at the end of each leg of the "L". Each of the horizontal bars has a piece of 2X4 screwed to it at 90 degrees (toward where the cab would sit) on one end. The cab would be placed in the cradle ("L" frame) so that one of the 'claws' reaches into the cab at the rocker panel and the other reaches in along the rear of the door frame. Then another pair of horizontal bars that mirror the attached set are placed in the opposite door in the same places as the other bars and then screwed (or bolted) to the attached arms. This will allow the cab to be secured to the bracket with no chance of 'accidental separation', and allows the cab to be pivoted and supported for just about all work that needs to be done.
Sorry if I have just thoroghly confused everybody!!
