Why would you want a trailer that is 7.5 wide on the inside
All the early (pre mid 1980) enclosed car trailers I look at where 96.0 inches overall width on the outside, mid or late 1980s they started offering the 8.6 inch wide outside enclosed car trailer, much better than the early 8.0 ft wide car trailer
Maybe being old and big (6.0 at 260 lbs.) I need more space to put my B and E body race cars in them, especially the E body's