Hope these help. If you need any other measurements, let me know and I can get them when I get home tonight.
Was hard to measure and hold the camera at the same time, but I think this is accurate:
This is the back side of the target assembly:
In the Mousin' around Manual, the part # for the target bank is C-12464-1
In the Black Knight 2000 manual, the part # for the target bank is C-12464
I am 99.9% sure they are interchangable. This was a year where Williams owned Bally, and these machines came out the same year, so it would be really odd for them to have made a new 3 bank target for one or the other machine.