Lift Headliner for Shoulder Belts

For 68 model the factory moved the coat hook rearward a few inches and put the shoulder belt anchor where the coat hook was, right above where side glasses meet. Your coat hook sits on a bump out in the roof structure. To flatten that bump out with a hammer is dang near impossible. You can make it disappear with a hole saw. A plate of some size with a 7/16 fine thread nut welded on will need to enter though one of the larger openings so more headliner to drop.
I did all this while replacing the headliner in my 67. Don't have coat hooks now.
My homemade plate is attached with 1/4 inch steel pop rivets. I borrowed pneumatic riveter from local body shop. And after all that I never did install the shoulder belts. My bucket seats don't have latches on the back hinges so in the right kind of collision the shoulder belt might do more harm than good. Only a crash test dummy knows for sure.