I think probably the best way to match it would be to get a sample from your machine and take it into somewhere like Bunnings and see if they can scan it and match it.

Pinball Universe http://www.pinballuniverse.com/PinballPaints.htm actually have THE paint, pretty sure they bought the formulas but they won't give out the details nor can they ship a tin of paint internationally. 

One last option is http://www.pinballpal.com/colors although I am not sure anyone ever got it spot on and whether the formulas can be deciphered here in Oz. 

Let us know how you go though, I need some myself.  As you can see I did look into it but that is as far as I got.