I replaced the factory seat in my 77 along time ago (It's still in the attic in good shape ) with a Leather "Qualtex" unit. It's still in good shape too ( gray leather) but it's too large for me. Back rest hit on the back window,flat with no bolstering on the sides to hold you in. I think it might have been happier in a van or RV.

SO...., who makes a nice aftermarket setup, buckets with flip up middle console/seat and some side bolsters to hold you in?

 

I would start here...

Bench Seat - PRP Seats

PRP Seats, very nice stuff and not that expensive.

 

I would prefer a "custom fit" manufacturer who is already making one to fit