If you have plastic trucks you can make homemade center rail pickups.
The light pick ups were made for the car below from brass shim stock and added to a non operating Lionel plastic coupler truck. A piece of tin can was added to improve durability of brass shim stock. I have made several for Lionel box cars that I converted into a gold bullion car, stock car into chicken transport car and aquarium lighted car. I also make light pickups for several Lionel 2400 passenger cars made from replacement shells and roofs.
These homemade pickups work better in forward operation with the pickup on the rear truck. Forward for the car below is to the right.
Charlie