I had trouble recently with a Neo Geo CD console that I imported from Japan, which was slightly damaged in shipping with a broken CD spindle hub. I'd substitued it with a PS1 spindle while waiting for proper replacements from Aliexpress.
The original spindle hub's plastic stem had snapped into 2 pieces and 1 piece was missing. As luck would have it, as I was cleaning up the console I noticed something rattling about inside. So I tipped the console upside down and gave it a shake and out pops the tiny missing piece of plastic.
So I decided to have a go at repairing the original spindle hub - I glued the 2 pieces of the stem back together with super glue and then decided to reinforce it with some heatshrink tubing, since there was plenty of clearance to allow this. Worked a treat, popped the original spindle hub back in and it's as good as new again with the original part.
The console came with 2 controllers, 1 of which had a dodgy direction stick. With some contact cleaner applied vigorously to the Left & Down microswitches and a tiny bit of force, managed to get all directions working again. It's working but I'm not totally 100% happy, it seems ever so slightly less responsive than the other controller. So I'll probably open it up again and try submerging the microswitches into IPA.