Fascinating! I remember the piece from my old Augener Mozart edition, which includes it though with the warning that its authenticity as Mozart was doubtful.
Just found the following poignant paragraph on wikipedia:
"
There was no composer whose works were more frequently passed off as Mozart's than Eberl. Even more surprising was the documented fact that there was no protest from Mozart against the use of his name on Eberl's compositions. Eberl, a friend and student of the great man, did mind but was too timid to take action until after Mozart had died. Finally, he published the following notice in a widely read German newspaper, "However flattering it may be that even connoisseurs were capable of judging these works to be the products of Mozart, I can in no way allow the musical public to be left under this delusion." Despite this, his works still continued to be published under Mozart's name.
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