Stainless steel driver seat back panel mouldings

You would need to see this trim rusted badly to know it isn't stainless. Anyway...
Some earlier model a-body buckets do have the same backs with chrome trim. Well almost the same. Earlier trim will have little clips inside it that attach it to the back. Your 67 should have dimples stamped in the edge of the back so those little clips were no longer req'd. You can leave the clips in there, just slide them to a location away from the dimples. Hope this helps