folding jump seats

Hello! I am fixing up my 1998 Land Cruiser, and for some reason it is missing the fabric that holds the seat strap when not in use. Does anyone know if this is a separate part that can be purchased, or has anyone found a fix for this? The grey interior is the one missing the piece (obviously)...

Back and bottom metal panels extremely straight with no issues, dusty from storage, restore or use like is. $500 for the pair.