I‘ ve got the same expierence with the seat of my old MINI.
At first the Seat was a little lowered an I wonder that there is something different. But than there was a strange noise and the webbing
was totally down.
Don‘t know how the MOGs webbing looks, but sometime parts of other British cars will fit. The MINI one?
https://minispares.com/product/Classic/Interior/Seats,%20belts/HGD100150.aspx?1705&ReturnUrl=/search/classic/Seat.aspx|Back%20to%20search
Greets René