It's a case of the Proof of the Pudding, so to speak. Birmingham made boxlocks can vary in quality and it is the gun you should buy in light of its quality and condition. Milburn would not have made the gun but sourced it from the trade. I have been in Brampton many times which is a very pleasant village. Milburn has long since gone and there are no shops there now trading under that name. I do have quite a few Milburn cartridges in my collection. The village location is on the border of Cumbria and North Yorkshire and close to Northumberland. All good grouse moor areas. I should have thought he would have done a brisk trade in cartridges and guns too to some degree. My best advise is to have a good look at the gun and buy with your gut instinct. Lagopus.....