Another Seat - disabled belt mounts

[mikey9]

Our camper was first reg as a disabled vehicle.

It has two strips in the floor into which a lap belt attatches at various positions along their length. I can only assume that the Wheelchair had it's brakes on (!)- and they put the lap belt over their ...lap.

Will post some pics

Now I was wondering if I could sort out an easy to attach/remove extra seat as I unusually have the seatbelt bit sorted.

Any ideas on the seat - ideally something not massively heavy - also on ideas releasable mounting clips.