FS 4 interRoyal adjustable metal swivel drafting machine shop kitchen? chairs fr - $500 (Naperville)

4 chairs.
3 are in good working order, the last one works but the seat moves around a lot.
Almost like there’s a gasket missing or something.
Will update if I’m able to fix before they’re sold.
$150/ea on the 3 100 on the one that tilts.