[Dave at Pelican Parts]

The side-shift console has an O-ring, not a gasket. If it's sealing well, you can remove it after draining the transmission fluid and just re-install it. Might not be a bad idea to have a spare O-ring and more transmission fluid around, though.

However--you should be able to remove the front shift rod from the shift coupler (the universal joint thing just aft of the firewall) so you can slide the rear shift rod backwards, then forwards again underneath the car. That will let you slide it out of the side-shift console to replace the bushing.

I believe that what you have found inside the tunnel is correct.

--DD