Hi Jon, that’s interesting must have a different style rear seat to my ‘std coupe’ cushion ones or a different roof cover maybe.
My roof folds fine it’s just that the inside roof cover studs are not there as the rear seat squab is!

Maybe a pic at some time would be most interesting..

FYI, Mine uses lap belts only in rear, not 3 way inertia style belts.

Regards, Robin
PS I don’t suppose Laurence has a cab backboard (squab panel) BBC2260 on the one your breaking, just a thought..