Landrover 90 Retro rear seat fitment

Evening All.

I have a regular good customer who has asked about a Land rover 90 63 plate and he is wanting to have

installed 2 rear seats which fit on each arch and the seats are 'side on' or facing each other.

He can have a simple lap belt installed with these or a 4 point harness for each seat.

He is being told by different sources that from and mot test point of view he can and cannot have these installed.

As these seats are additional and not designed by the manufacturer I would appreciate your opinions and views so

I can give him the correct advice.

TIA

Deano