This is the last pinball machine from this manufacturer to use a silkscreened '1' for the thousands digit in the score. Subsequent games used a score reel in this position for higher scoring. The add-a-ball version of this game is Gottlieb's 1967 'Diamond Jack'. The add-a-ball version for export to Italy was Gottlieb's 1967 'Solitaire'. The game was also produced in Spain as Petaco's 1967 'Rey de Diamantes'. The production games have red numbered inserts and red-on-white roto-targets. The game in the manufacturer's flyer has black numbered inserts and red-on-white roto-targets. Pictured here are two sample games with serial numbers 01028S and 01003s. Both have black numbered inserts and black-on-white roto-targets. On these samples, the factory never installed certain posts near the K and Q targets and the J and 10 rollovers. The untouched dimples that mark the post locations can be seen in some of the pictures. These samples also have decagon score reels showing the shorter and thicker numbers as seen in the flyer. For game 01028S, we can't validate why the center pop bumper cap and skirt are yellow, not red, but this color was not changed by the owner. Game 01003s has a coin entry plate showing "2x5c" instead of "5c" as seen in other games. On the lower right corner of its motor board, next to the Extra Chute Adjustment jack, are two dimples to mark where a Triple Chute Adjustment jack would be mounted as seen in other games. In the motor board center area is a 2 Coins Per Play Relay while game 01028S has only dimples in this area and the one production game motor board picture we have shows no dimples there. Closer to the transformer, three sets of unterminated wires extend from the main cabling near where two relays are present on other games.