Need help Identifying Part

[montrosepatriot]

with a 3D printer the panels for the 78-91 (underneath the seat belt retractor with the integrated bolt hole 4 the anchor) can be fabricated from 18 gauge sheetmetal; most of the GM part #s which I have abstracted from several parts catalogs have been discontinued and GMC Paul's only has reproductions to 1972 only (squares not included since we're the redhead stepchild and using overseas sheetmetal 2 repair rust)