One of my favorite SS titles - Great game !
Check the backglass - unless I'm mistaken, this will be the LAI produced machine - should be denoted on the backglass (although I might be thinking of Meteor). The Stern headbox is a pain to paint. The backglass surround is made out of chipboard, not timber, so it does not take to painting very well unless primed.
This particular cab looks to be badly scratched, which was uncommon to see on Stern machines. Their paint jobs were much more durable than Bally and GTB.