I would contact my local Building Officials and also my State Inspection department as well.
Most modular companies have a State inspection sticker on each componant of the building.(look in a closet or cupboard to find out what department signed off on it.)
Your local Building Inspectors will perform the Occupancy Inspection before you move in. Ask them about this patch work and structural integrety?
I own a 28 x 48 Colonial with a 12 pitch that I refer to as a "double decker - double wide "
It was very impresive to watch the four boxes go together. It was not until they were gone and I started to do the inside trim work, did I realize the house was set 3/4" off. The boxes did not line up.
I would do it all again but, I have learned alot the hard way!