Newbie - '90 Holiday Rambler Limited DP Sagging Ceiling

hi Mike
Thanks for the instructions... here is an overall photo I took.
I hope it posts OK.

It's sagging in the rear due to an air leak I haven't had a chance to address yet.
It does come up fairly quickly, and the primary & secondary reservoirs retain pressure for hours after it's shut down, so i hope it will be a simple fix.
The paint job is a 15' paint job... looks graet from 15' away, but as you get closer, it looks less good - LOL