It is an open book, and it is yours, do what you want with it. Remember the supports and front to back and side to side weight issues.
Take a door off and go to Home Depot, Lowes, Mernards... etc and see if they can match something up.
2013 Forest River Salem Hemisphere SBT312QBUD
2001 CrewCab F-250 7.3 PowerStroke Diesel
SuperChip, BTS transmission, 6.0 Trans Cooler