Does anyone know if there is any difference between the English Rio Grande version of the game and the German ABACUSSPIELE version?
There are differences in the rules.
The RGG rules are at http://riograndegames.com/getFile.php?id=568
The Abacus rules are at http://www.abacusspiele.de/?m=spiele&action=download&pdf=299
The RGG rules introduced an "Alternative Share Supply Deck Rule."
There may be other differences.