[travelin texans]

With exception of Winnebago (yet) all the above mentioned rvs are now owned by Thor, so you probably wouldn't still be able to get drawings.
As stated, even if you were to get schematics they most likely wouldn't be "as builts" but merely suggestions for the folks on the assembly line that put them together as fast as they can, if they had to pause 15 seconds to look at a blueprint that would throw a monkey wrench into the entire assembly line.