Yup, they sound like originals. The threads are for plugs with a 24mm hex on the end and a central 6mm thread that the bar end weights bolt in to. The hex plugs are useful if tou want to use the original weights or, alternatively, some Stelvio hand guards. These come with their own, longer, bar end weights but use the same 6mm bolt, albeit a longer one, for attatching the weights and then the hand guards.
I've probably got a pair of second hand plugs knocking about off one of the wrecks if you want? Got hand guards in stock too. Not sure about original end weights.