Picked up a pretty decent 16ga NID today and have a couple questions I know can be answered here. First it was made in 1936 and has no cocking indicators, I was under the impression they had them till the last couple years of production,what was the changeover date on them? Second question, are NID stocks interchangeable, as in slide one off and another on like modern machine made guns? What pad would have been on a 1936 gun from the factory? This gun feels good and handles well and doesn't really feel that heavy but on the scale it is 6lb 11oz, is that about the norm for a 16nid? Thanks in advance.