www.usedpartscentral.com/used_chevrolet_parts.htm and www.ebay.com are two places where you should be able to find a seat for your 1979 Chevy.
where can I get a seat for a driver for a 1993 chevy grumman truck
YES.
no not without modifications
How do you replace the front drivers seat on a 1996 Chevy S10 pick up truck
any seat belts from an 1981 through1987 Chevy truck or 1981 through 1989 blazer or suburban
Unbolt it from the floor.
Truck seat covers for Chevy truck can be found at the Chevrolet agents. if they do not have in stock they will order for you. You could also try to go to auto car spares shops, they might be able to help.
Put your seatbelt on!
At the botom corners of the seat you will see a loop strap just pull on that and lift the seat
Probably needs lubrication and the control cable adjusted
The best place to find a used Seat Leon for sale is at your nearest Seat dealership. Their website and that of other Seat and used car dealers are also a good place to check for what is currently available for sale.