You can get them at your GW dealer, it's probably the easiest.
(pretty sure they are dealer only item, could'nt find them anywhere else)
If you have the same ladder back chairs as I do on my 1994
Sailfish, the are still available, as well as the nylon slide bushings that
the chair slides back and forth on if they are slider seats.
I got all all new slides (two a chair) and two new swivel cup bushings,
I think I came to like $60 to $80, but not bad as compared to $400 +
for new seats. Hope that helps.
Tony L.