rear seat belt Mondeo

[sphinxy]

i have an R reg Mondeo the middle inertia reel seat belt got jammed with the seat back in the down position it would not move and as i had to get home with passengers i had to cut it to get the seat back in the up position after looking into this the inertia reel in the back of the seat was damaged i have replaced this with a static lap belt from an older version Mondeo is this legal will it go through the M.O.T with this. the two window back seats are fine it is just the middle seat

[VHG]

This may be best in Motoring or Cars.

You have it in Travel which is mainly holiday type travel.