I have a 73 4905A that I removed the tag axle.
I looked at a few that came standard without the tag axle before I removed it.
The bay structure of a non-tag equipped bus looked just like the structure for the other two forward bays.
The easy part was cutting out the A-arms and removing all the stuff attached to the big C-channels.
The hard part was designing and fabricating a structure for the floor that would give adequate strength for the weight of all the tanks and provide replacement strength for when the C-channels were eventually removed.
I did take out the Big C-channels(the ones with holes in them), but only after I was satisfied that the floor structure would provide enough strength. If you look closely at the structure, those tubular things in the center and edges of the bay next to the door actually do very little other than keep those walls from pushing out at the bottom. Again if you look how the C-channels are attached, you see a lot of bolts and a stiffener on the opposite side of each wall, but the bay walls themselves are not very stout.
I got a good price from a respected bus parts place for a take-out floor, but to get it out it would have to be cut, and all the rivets drilled out. To get the original strength, I figured that the floor would have to be installed the way it was at the factory, but some of the parts were no longer straight or even. Plus cutting the B-decking would severly reduce the rigidity, which would have to be spliced, and where would I get that piece.
I ended up using a combination of 1-1/2" x 1-1/2" x 1/4" wall thickness and 1-1/4" x 1-1/4" x 1/8" wall thickness mild steel tubing and 1-1/2" x 1-1/2" x 1/4" thickness angle. The 1-1/2" square tubing has the 1-1/2" angle welded to it to form a shelf. This slips inside the aluminum C-shape on each bay wall and is bolted through the walls with cad-plated bolts and washers. I would have used stainless, except for the cost, and the original bolts were steel. Then on top of this "shelf" I sat the 1-1/4" square tubing ladder frames, clamped them and bolted down through vertically. When I put the 3/4" plywood on top, the floor will be flat. There are actually three frames; two identical "ladders" on each outside toward the bay doors and a wider one in the center. I will try to post pictures when the temperature outside gets UP TO FREEZING!!!
My only fear with the structure I created is that it may not flex as much as the original structure would have.
My plan is to get all my utilities in there except for AC& DC Power. I don't like to mix liquids and electric!!!
I don't feel so bad about not working on the bus tonight and being inside on the computer
But, you have to do what you are comfortable doing and living with.