Seat belts

I need to correct.
After further investigation and thought it appears the front seat belts were changed with 1969 ones.
I suspect a PO did so as some later parts are on the 67 car's drive train like a 489 case 4 speed and engine. (block casting)
Why he chose to change the front belts is a mystery.
The rear's are original.
The 69 front ones show age and certainly were in the car a while.
It was last on the road in the 80s.