https://www.rvt.com/Barth-Rega...e&utm_campaign=oodle

see pics

Building less than 25 hand-assembled units per year, Barth is still considered a premier line of Motorcoach, with original pricetags in the 80K-150K range in 1980’s dollars. Most manufacturers build on wood with aluminum skin or use fiberglass.
Barth is an all-aluminum construction far ahead of it’s time. Much like a jet aircraft, a Barth is an aluminum skin placed over an aluminum skeleton. That means no rust, no rot.
The aluminum substructure is riveted in place using a total of 2,120 rivets. Each rivet was installed by a two-man team. The superstructure in mounted to a heavy welded-steel chassis - in this case, a Chevy P-30 chassis with a Chevy 454 engine.
Driveline and engine parts are easily accessible because of this assembly.