I have a complete set of seat sliders for (I believe) A-body bucket seats, but when I compared them to the ones in my 70 Dart GT, the mechanism is different. The 1970 style has two tracks but one track does not sit inside the other like nested "U" shapes like these have. If you know what they are for I'd love to know. One weird thing about them is there is no locking mechanism for the sliders next to the transmission hump, just on the ones next to the doors. There is no pivot to attach the handle on the outside to the slider on the other side of the seat.
Last but not least is this slider that has no piece that raises the seat off the floor: