Rear Bench Seat with belts 1997 defender 90

[jdean44]

I am purchasing a defender 90 1997 model with rear jump seats and would like to add a bench seat with belts so my little man 2years old can have fun with dad. Just need to strap in the child safety seat forward facing. Local Cinn. OH dealer says they can't get one even though you see them in other 97 defenders. Can anyone point me in the right direction.
Tx, jdean44