My 84 tintop with a westie interior, the brown tweed seats were/are about
gone...They were uncomfortable, especially the driver's side.   As a simple
fix, I found some memory foam "chair pads" at a bimart store...brown cord
covered firm memory foam about an inch thick, with sewn-on tie-strings to
keep these in place...Made for hard wooden  chair seats, but they've worked
surprising well.  An unanticipated benefit is with the little height gain
they give, my Vanagon can now be driven like an old split window bus....
you who owned old hippie busses surely remember that "stance".