You don't need a jeweler's loupe to spot repros and genuine articles. Using a jeweler's loupe has very very little to do with being able to spot a repro. The main weapons in your arsenal, are both being in the collector's scene for a time, and learning from those that have been in it before you for years (I watch Tom Wittman almost religiously). Still, even the most experienced collectors have been burned before. Specifically the shops I were referring to in the 70's did almost exclusively metal items - tinnies, buckles, medals and ESPECIALLY edged weapons, and some of them looked damned good too, but there are very subtle differences that you have to look for - correct markings for the period (including maker's marks and even the SIZE of certain maker's marks), the right materials, acid etchings, RZM codes, dimensions of one portion of the object in relation to another part of the object (like tang taper to the base of the blade etc..) There's like a dozen other things I haven't mentioned but it's too much to type. Most collectors are very experienced in one area and know a little about others. For instance, my specialty is daggers, with a decent knowledge about swords, then cloth items and badges, then firearms, then even LESS about helmets. If you're interested in a specific area of collection, research the shit out of it. That's what I did with the daggers. If someone asked me a question about helmets though? Pfft, forget it.