You might like to ask this question on Expedition Portal ,
https://expeditionportal.com/forum/forums/hard-side-truck-campers.119/ , There is a wealth of knowledge there .
I have a home made camper for my '40 , built as light as possible (I thought)
it weights 610 kgs. Apparently that is VERY light, expect the Little caboose to be much heavier , I see on google , they were last made in 1978 , so not an era of light weight composites .
I would guess that a 3/4 ton would be the lightest truck to carry the caboose . Then some additional work to over load springs , sway bar and D load range tyres .
go for it !!
