I have kept serial numbers and machine numbers (example 2442 of 2500 Batman Forever) for all my 40 x dmd machines....I find it interesting to see how many machines were made, and what number along the production line each machine was......
The AC/DC Pro I have, I have also kept the machine number for it as well (cant remember the exact number it is but it was a number over 500 which must mean they planned an initial run of AC/DC Pros of 500 before they started another run of LE or Premium or whatever) etc.....
Some of those numbers on that list look very very low...Shrek should be 500 not 50 for example......the others, who knows, but its a start !
That link Swinsky used above takes u to the end of the thread, try this one which gets u to the start if u need to.
http://aussiepinball.com/index.php?topic=9385.0