I like the idea of testing although I think that it has to be analyzed in the context of the time, versus current standards. A metallurgical (spectroscopic) examination of some TR daggers a few years ago, elsewhere commissioned by a serious collector, yielded interesting results which I personally found quite surprising.
Very often a byproduct of mining other metals, Germany was not noted as being a major producer of silver, and was in fact importing it from other nations (1936). My point being that it�s not just time. Location of the ore source is important along with some other variables.
I�m also more than a little perplexed by what is considered an �Offermann� style chain, and how do we know what it is made from using the black and white photo? Clearly the chain set shown being worn by Offermann in the photo is different from the many silver chains sets now in circulation on the daggers (those with the fake �Gahr� and other markings). As I think can be easily seen in the image below with the Offermann photo on the left. FP
