My MH has been wallpapered since 95 slight bulge at seams in panels beneath. They didn't use pre-pasted home owner width rolls, possibly full wall height. I haven't looked for a horizontal seam or any for that matter but real big sheets . Commercial wall covering for sure. I think they use clay based glue back in the day and still do but there's newer super HD clear stuff now .
You could see if you can contact company like Roman for advice for extremes of MH.
95 Monaco Crown Royale
M11 400hp, 4060 trans.
Aquahot, Generac Guardian7.5k