Well, while bolting the driver seat back in the car, I realized that there seems to be no seatbelt (in a way....)

the seats are very aftermarket... the right side of the seat has the seatbelt buckle, but there's no place for the seatbelt itself.

I have 2 questions about this.
The first would be, how were the seatbelts mounted originally, in the 70's? Were they attached to the seats, or so the hump / side of the car?

If they were attached to the seat, I suppose I could try to see if there's a way to attach it... Doesn't seem likely, though.

Also, legally, were seatbelts an option in the 70's? or were they mandatory in all cars, at the time? If by not having a seatbelt to buckle, then it shouldn't cause any problems, legally, right, if they were an option at the time?

I havn't found any documentation about what came in this car, originally. (Stupid stupid previous owner(s))

 

I assume firebirds and camaros are not that different so...

The seat belts do not mount on the seat - they mount on the hump/side of the car. As far as I know, they all came with seat belts - mandatory option that is. In 70, the front though you could seperate the lap from the shoulder if you did not want to wear the shoulder belt though.

 

My 70's belts bolted to the floor pan, the shoulder strap was seperate from the lap belts and bolted up on the side of the roof line.

 

What they said is correct but I might add that there were two belts (with the buckles) on each side of the hump (the extra one being for the shoulder belt) and one retractor belt on each side attached to the floor by the door.

 

on a side note, seatbelts were definitely mandatory at the time (1970).

 

I concur with these guys. The seat belts are a 2-piece system, where the lap belt retractor is bolted to the floor inside the door, and the buckle is bolted to the hump in between the seats. The shoulder belt is bolted along the inside of the roof line, and tucks underneath a small plastic cover when not in use, but has a pin that clips into the buckle of the lap belt when you want to put it on.

Don't worry that the seat belts aren't attached to the seats!