Wanted: plastic cover for fixed seat belt top mounting

[Cooperbloke]

Hey all. I've got a 1974 South African Mk1 2 door Escort and I need a specific interior part.

There's a plastic cover on the top belt pillar mounting that doubles a place to hang the belt buckle when not in use.  

One of mine is missing, and I've no idea where to find one. I've never seen these before, but I may just not be very observant!

Anyone have one, or any suggestions on who may have one or know the best place to find one please?

The belts work perfectly, but if I can't find anything, I'll retrofit a set of inertia belts so they don't lay on the seat or floor. 

Thanks for your help!