The front wrap around
windows and sloping back have the general proportions of a vintage Franklin grp (glass reinforced plastic) caravan. It's probably not this 1969 model, but you get the idea.
Vintage Caravans - Franklin 14ft fibreglass caravan
BTW, I wonder what became of these curved plexi
windows in trailers. It seems like everyone thought they were the future, but you almost never see them!
Regards,
Matt