I can't help with the mfg although as one reply said knowing the brand or mfg name won't be of any help with construction blue prints/or any tech info.
It is a slide in truck camper of that late '50s/'60s era.
I had a new '67 48" tall slide in with the interior layout just like it on a '67 chevy.
Exterior was a bit different with double doors on the rear. The mfg of the one I had went out of business around '80.
Later models came with 5' then 6' and 6' 6" ceiling heights till finally the TC industry gave us a 6'+ tall slide in with a over the cab bed.
