If it helps, if you have either versions -01 and -02 with the -1 revision of CPU code, DIP4 @ R8 doesn't function (trackball speed). If you're using an upright (and I'm pretty sure you are) then no problem.
-2 revision of CPU code introduced the ability to switch DIP4 @ R8 to ON - to indicate that the smaller mini-trackball was being used. I'm not entirely convinced it was a problem with the cocktail (I too used the -1 revision of code im my cocktail without any issues). My personal pet theory is that swith DIP4 @ R8 was introduced when the cabaret Missile Command rolled off the production lines. I think this because the -1 rev always knew when it was sat in a cocktail because of the second set of controls plugged into the board (and that as well as screen flipping, the board also took account of the mini trackball). Wouldn't have happened in a cabaret though as only one set of controls would be present.
Like I say though - that's pure speculation on my part.