then probably the latter spelling! due to the fact that the German form is Alemannisch. The Germanic tribe can be referred to as Alamanni, Allemanni, or Alemanni.

http://www.modellbau-quedlinburg.de/mbq/cms/front_content.php?idcat=142

that website has all of the joints used, but doesn't tell you exactly how they are used. maybe I should undertake this project to create a book on Historic German Timber Joinery.