Convertible to Add-a-ball. The Add-a-ball version of this game is Gottlieb's 1978 'Neptune' which was exported to Italy as Gottlieb's 1978 'Poseidon'. We previously showed a confirmed production run of 375 taken from Gottlieb non-engineering records. That number may have been a transcription error based on this information: Gottlieb Domestic & Export Sales Sheets for Hit The Deck: 575 total Domestic Sales: 166 Export Sales: 409 The above total does not include 2 Sample games produced in 1977 per handwritten documentation identified by Wayne Neyens as coming from Bob Malvasio, a draftsman for Gottlieb whose initials RHM can be found on schematics.