Thanks for all the technical suggestions.That looks like a thrust roller bearing pressed into a custom brass housing. if you find the envelope dimensions of the bearing it shouldn't be too difficult to source, the housing will need to be custom made for sure though.the bearings assembly namely... you'd have to find a replacement. look at that thing lol
3D printing can actually make really good gears if they're made right... HOWEVER they really need to be printed in nylon for wear resistance and strength (which require a very high temp and fully enclosed/temp controlled printer). And they need to be made with a printer that has a high chassis rigidity (fully framed printer, not one of those cheap ones with only center posts) because any vibrations or skewing of the axis during printing will be quite noticeable in the final printed part and you'll be able to feel it in the action.the amount of gears to replace, I'm not sure if you can 3d print them with good resolution enough and injection molding that many different parts...
I honestly would not recommend metal gears for this, they'll be very noisy and have a much shorter wear life than nylon gears, require more regular maintenance to keep them greased, put more drag on the spinner action not to mention they'll be more expensive.
I'd be willing to bet you could find adequate replacements off-the-shelf as there are a lot of plastic gears available for everything from paper printers, to RC cars and Disc drives.
We will see what's come out.
For sure it's easier to just use a Taito spinner and mod it using the repro topper and the button….