If you've already tried the first step by observing what happens outside and in during a heavy rain - making sure that water is redirected away from the foundation by making sure that the gutters are working correctly, the downspouts are emptying at least 6' from the foundation, and that the soil is graded away from the foundation - and you're just looking for a quick fix, you might try plastic or fiberglass wall panels.

You can get 4 piece fiberglass shower shells that will allow you to get it through the doors.

Shortly after he moved in he managed to put a foot through the fiberglass bath tub, which we replaced with a cast iron tub. 

Mold testing revealed it in the ceiling of the basement, water damage was evident when the fiberglass insulation was removed. 

Just spoke to my handyman & he said that (as Greg B. stated) mobile home doors are odd sized & a combination Aluminum & Fiberglass in many cases. $400 is about right according to him.mobilehomeparts.com is a website that my handyman uses to fix his mobile home client's units.

Took out about 5 inches of drywall across three feet and the wall feels solid everywhere else except where the drywall meets the fiberglass tub/shower combo.

Cheap fiberglass?

They came in and used material that has fiberglass and left it all in the floor of the basement.

Just clean them up and recaulk, and clean the fiberglass shower unit or epoxy it.

Fiberglass (pink) or Cellulose (brown).