Re: Ibanez case "FUR" or "LINING" replacement
It may be a long & treacherous quest trying to source the exact same material...wish I could tell you where to start! Are you only looking specifically for "authentic" Ibby case material, or would a worthy imposter suffice?
But in the meantime, or as a fallback plan...most fabric or craft stores like Jo Ann Fabric & some AC Moore/Michael's, & even certain Wal Mart locations have a pretty vast & eclectic selection of all things fabric/material. In addition to the typical types used for clothes, curtains, & whatnot; my local Jo Ann has some pretty wild stuff!
Specific to your needs, they also have a ton of different crush velvets, plush stuff, & an impressive overall-selection of the types of materials you'd expect to find in an instrument case.
Just an assumption, but whether it's an Ibby, Fender, or GuitarFetish case...one constant ingredient usually includes one of the above materials glued via spray adhesive to the axe mold.
Good luck with whatever you decide.