i never had that problem with my system 11 wms pins(with the 4 seperate diisplays), they just clock over to 0,000,000 then when you get to the end of the game it shows up as 9,999,999 or 9,999,990.
and the 11b and 11c systems seem to just add an extra digit, but i have never got over 50,000,000 on the system 11's with only 2 displays. even the earlyer wms pins with sytem 7 clock over and give you all the 9's for a high score when you finish.


to memory the early bally's clock over and show as 99,950 or similar as a high score after you finish you game