67 bench with no headrest or shoulder strap

OK, so I have read every post I could find on the subject of adding shoulder seat belts to an a body, and from what I can gather a 67 will not have the connection point in the roof for the seat belt.

A few questions:

Can the attaching point in the roof be added?
I have seen a few aftermarket kits, but none have the pieces to attach to the roof.

I have a stock bench seat. Can headrests be easily added?
I think bench seats with headrests have a different internal structure.

Would I need to, or would it be easier, to get a bench seat from a later a body?

Token pic of my seat.

I also want to redo my bench as it is starting to tear at the seams due to use, and it is not very comfortable, so I am thinking new foam and a new cover is in order.
Before I do that, I need to figure out the headrest deal.

I would like to keep it stock, but when it comes to seats, headrests, and belts, I prefer to upgrade.