[BILL]

Upon looking at many pictures of Lugers, and held many up close, I am wondering about how standard was the practice of proofing on the grip screw? I know we had some excellent technical dialogue in the not too distant past regarding manufacturing processes and finishing procedures but what firms actually proofed the grip screws, what years was this prevalent and if you see a pistol without the proofs would this mean that they are add ons? Honestly, I have seen very few pistols with good original screws that were proofed. And what were the common years that they were fire blued as opposed to rust or dip blued? Since these items are the most commonly removed items it would be nice to know just what to look for in the line of 'good screws'.