I have several sets of 126 B pillars in the shop. All have the vinyl ripped &/or off the pillar itself. All have crumbling foam.

I believe that the process would be to find and cut 1/8" foam to fit the vinyl then attach the vinyl and foam using one of the 3M products. Leave enough exposed vinyl to wrap around the pillar. This bare vinyl edge is glued to the pillar using a brush on upholstery glue. Use clamps to hold in place until the glue sets then stretch tight and do the other side.

So...glue foam to vinyl. Then glue edge (only) of vinyl to B Pillar. I say this because an unmolested B pillar aluminum only has glue residue on the back side edge of the aluminum.

__________________
85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.