A good question. I can say that he set up in business on his own in 1883 and was making guns as William Evans from Purdeys at that time. He only worked for Purdeys for a short time prior to 1871 and then only in the shop sales part, not in any respect with gunmaking. He then went on to work for Hollands until he set up on his own. Working for Hollands for longer than he did for Purdeys I wonder why he didn't mark his guns Willian Evans from Holland & Holland. Purdeys never seemed to contest it and indeed Purdey had signed some of his guns as being 'From Mantons'. I suppose they couldn't say much as it was not a lie as such. I have found a 1923 advert for Evans' guns but no mention of Purdeys by this stage. More digging required but that narrows it down to a 40 year period. I have quite a few old William Evans cartridges so will have a look at those to see if there is a Purdey mention. Until then I'm sure someone will have the answer but that's the best I can do with a quick look. Lagopus.....