Plans? Or at least hints at construction?

[RKDowner]

2014 Keystone Hideout 23RKS travel trailer.

I'm mounting solar panels and installing wiring, solar converter, etc. and need some guideance. A few people online said that they've contacted their manufacturers and received blueprints showing where all the studs and roof joists and such are located. I contacted Keystone and they said this is proprietary and they won't share it with me. Can anyone help me, beyond recommending a stud finder? What is the roof, 3/8 in plywood? Are the roof joists on 16-in centers? How wide are they? An inch and a half, an inch? Are the studs on 16-in centers? How wide are the studs? How much space is between the roof and the ceiling? How thick are the walls? These would all be helpful to know, but somehow Keystone considers this proprietary.

Keystone basically told me that I need to take it to a Keystone dealer to have something done like installing solar panels. This is ridiculous. I will go to the dealer to have my slide-out serviced, I will go to the dealer to have my refrigerator repaired, but I don't need to go to the dealer to attach some clips to the roof.

Any help will be appreciated. Thank you.