Of course André, but have a look at the sidearts
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O LOL, stupid me I hadn't looked at the pictures on the actual ebay ad !
Mmmm, notice that there is no 2084 on the side.....so maybe this was a factory thing ?
I don't know which game was released earlier, KLOV says 1982 for both games....
Notice the Joust bezel is missing.
[Edit] Thorsten you are right our Jousts have the ostriches. Maybe the artwork wasn't complete yet during production and they wanted to get out the machines ?
Of course it could also be an after market conversion but it would be rather weird for two games released in the same year.