Renault Trafic 1985 Autosleeper rear Seatbelt

Hi all
I am just going to look at a camper and it appears on the photos to have 1 seat forward facing in the back but no seatbelt. Does anyone know if there is a retrofit kit for this?
Here's hoping

It may have a belt that is hidden away out of sight. It's been quite a few years since I owned a Trafic based AS, but I'm pretty sure mine was fitted with a lap belt, and that could be made to disappear from view under the cushions or in the under-seat locker.

Retro-fitting is likely to be an issue. If AS did not make arrangements for fully load rated fixing points for an inertia reel belt then trying add one now is not likely to be simple.