The word "Gesellschaft" which your aunt found simply means "company" - it has nothing to do with the family, only that "Gsell" or "Geselle" means comrade, compagnion.
My Gsell-ancestors come from Alsace. One branche runs a beverage wholesale compagny, whose homepage you will find under "
http://alsaweb.com/gsell"
regards, Bernd Schwiers