its quite possible the mech has been reprogrammed at a later date,are you u.k or states?
money controls would have the information you require if you email them
you could use any credit board on that mech(as long as its set to parrellel) such as vts,excel or klingon
its quite easy to deduce which wires do what,i am pretty sure the orange is +12,green is common,white is credit line,brown is coin counter,can't remember if the black is another common
get your meter out and trace the wires,if i am correct the orange will link to the +12 jamma pin,white to coin 1 jamma pin,brown to one side of the coin counter(the other wire on the coin counter will be +12 or +6),the black and green to the common/ground of the jamma
check all this first and report what you find