Floppy Gearstick again

Hi all, back to the floppy gearstick again. I've narrowed my problems dowh to this part. Any ideas what this part is called. It's part of the gear change mechanism.
I've contacted Rimmer bros, as far as they know. The part is obsolete but he told me the parts that fail are called top hat bushes. Any ideas where I would get them if at all.

Contact Warren of Muddy Mods. He does some gear selector parts.

Thanks again