Check out this link for the Addams Gold owners list and read where Larry DeMar says that the European Games went out first so that would be correct that the one which you say is in the 70’s was in fact early production.
http://hem.bredband.net/b257182/TAFGlist.htm
I would look hard at the playfield between the two and go for the game with the better one as all other parts you can get if needed but that. Also, I guess does either have matching boards if that matters to you?
Finally, can either game be picked up in person as I guess shipping could affect your final cost if not.