I got it into my head that I wanted to play Marble Madness the 'right way', and so started to look into trackballs. After a couple of false starts, I settled on the Holland Computers RetroArcade trackball, as this supports a 3-button mouse configuration on Windows (https://www.hollandcomputers.com/store/pc/Track-Ball-2-inch-Arcade-Game-Trackball-for-PC-or-MAC-USB-Connector-2515p10641.htm)

This is the housing that I designed to make the trackball a stand-alone unit for use with RetroArch or MAME games.

The buttons are 24mm diameter, 34mm high clip-in arcade push buttons. The button +ve posts need to be soldered to the L, M, and R mouse button leads, and the -ve posts need to be wired together, and then a lead soldered to the exposed VSS pin on the bottom of the trackball.

The case is held together with 4 x M3 bolts, and the trackball itself is held in place by another 2 x M3 bolts (I also used double-sided tape to stop any shifting). If the black trim is wanted it needs to be glued in place - I used good old SuperGlue. And I gave it LRF support - I put little rubber feet on the base to protect the tabletop from the bolt heads on the bottom.

This setup works well with the classic arcade trackball games - Marble Madness, Missile Command, Centipede, but the ball also works as a spinner control, and so Arkanoid and Tempest also work nicely.