I came across this almost mint 1989 Williams "Police Force" Prototype by pure luck yesterday not knowing that it was a prototype when I picked it up (I'm new to pinball). I have looked all over the internet and cannot find any info on this prototype or what exactly they were used for. I do know they where originally designed to be Batman themed but was changed last minute. Any info on this thing would be helpful as it appears to be the only known prototype to the internet and I don't want to mess it up if it's anything special as it is immaculate and untouched!
I have attached a pic of the Serial Number sticker and the playfield, it matches in multiple places all over the machine.