The problem will be doing a visual inspection of the wiring, lightning can blow off all the insulation of the wiring but leave the conductors where they are not touching, even a megger won't detect this, on a stick built house at least most of the wall we use are the inside non-insulated walls, where we can run a snake camera down the wall to inspect the wiring, but in manufactured housing most of the wiring is installed in the ceilings or floors, and or the insulated outside walls, where it is impossible to do a visual inspection, the only way this home could be stamped safe would be to contact the manufacture and they send out a crew to open the areas where the wiring is located, the reason for using the manufacture is they will have the location of the wiring on file at the factory, if this is not done, I would not hang my name anywhere on this home, as open bare conductors inside of walls are a fire waiting to happen, it will cause pyro-carbonization of any wood in contact of a bare hot conductor, and while this takes time it will eventually burst into a fire.
CYA on this one, RUN!
I should say unless you can get the manufacture to give a letter of safness of this home, then the insurance should give the owner a total write off, as it will not be safe to live in, the cost to do a total rewire, will most likely exceed the value of the home.