1916 DWM Luger - Help Needed

[f100]

As a watchmaker, I’ve picked up on some great authenticity tips for original correctly age blueing effects but direct lighting my early straw37 shows a still nicely blued original remaining barrel. Then taking a higher lumin small hand held flashlight 🔦 pointed away at a correct angle the root beer effect of ghosting of aging underlying rusting showing up after 80 years . A newly blued barrel would not “ Root Beer ghost like this . Also ( the slide on my AC41 shows it off well too)