Modular home - marriage wall

Yeah, don't remove nothing Modular homes are very precisely engineered homes.
Contact the Factory that built the home or take the plans to an Engineer or Modular home Company and ask the questions.

Good advice, please take it.
When you say it's only a 4' tall attic ( I believe that's what you meant) that sounds more to me like a mobile home not a true moduler.
The clue is low pitch of the roof so it can be driven down the road.
If there's a steel frame under it, or it came on wheels it's not a true moduler.
Differance is there built very differant.

I live in a "Real Modular" the attic space is only about 4' or 5' high.

When it's shipped the roof is collapsed because it is hinged and is lifted when the home is in place. Once it's in place you'd never know if my house is stick built or factory built.