66 Dart-three point/ shoulder restraint?

Years ago on a GM B pillar car I welded in a threaded 1” boss. Left it protruding a bit then welded a small plate a top it that plug welded vertically on the pillar. Worked and the wreck showed it held.

Just no pillar this time. Maybe more detailed examination on the roof line to see it can be strengthened and still look good after headliner. Hahaha, just hope someone had already done it!