Trackball "boosters" from GGG

[Level42]

Has anyone bought some of these:
http://groovygamegear.com/webstore/index.php?main_page=product_info&cPath=74&products_id=283

I wondered how large they are and if they might fit a 2.25" Atari trackball.

The reason is that I recently played a full-size upright Missile Command and it played SO much easier than my cabaret does. Of course the big ball helps a lot. You only have to move it for a short distance to get a big tracking on screen.
With my cabaret it requires spinning like nuts to reach "all the corners".

So, I thought it would be great to use these instead of the normal discs. It's very simple, the holes are not as wide as the originals, resulting in more pulses per moved cm.

So I'm thinking of installing these on my MC cabaret. If they fit of course....(remember MC Cabaret has the full metal trackball:
http://forum.arcadecontrols.com/index.php?topic=81554.msg925193#msg925193 )