Yes, it’s the same here. The chassis is in Australia on a temporary export. Duties will be paid on the box only.Interesting project !
I'd say it will limited the roads to travel outside the US somewhat - but the need for comfort I totally understand.
Customs wise, this is interesting to follow as in Europe you'd call this "Temporary Export" and you'd only pay duties on the box - not the chassis. May I ask how this is in the US ?