Go to the IPDB site. Look for Archives, click on it. There will be 2 entries, Click on Engineering Cards. Read the intro, and scan the cards until your game disappears and that date will be a production date. The Copyright on the playfield might differ as the year ends, or the Engineers hold the engineering sample.

Well, your is a very very early sample/prototype game I think.....

Edit: Maybe long delayed in between EM and Soild state machines....ended with digital score reels.

The copyright date on artwork is not the manufacturing date of the game. The date that is recorded in the database entries is the start of manufacturing, not the start of game development.

The development process of a game can take several months to over a year. Somewhere in that span of time, the artwork is prepared prior to the actual start of manufacturing. And sometimes, the game's development crossed over into the next calendar year.

Additionally, in some cases, production schedules got shuffled around for various reasons, and a game that started development first ends up being actually manufactured in a slot that was a game or two after where it originally would have been.