Thanks to intrepid readers smarter than myself, it appears the mystery flashlight is solved. We got the tip to search for "Taschenlampe" on ebay Germany. It is a police torch and the filters served some sort of practical, policing purpose. Check out those elegant filter sliders on either side of the lens. Fucking fancy. The police provenance answers why it is of such high quality, but the Buster Brown mystery remains.
The flashlight above is for sale on ebay.de right now for 5 euros. Get a garage sale boardgame and make your own! But make sure to send me a photo and my royalty payment. I'm not picky, I collect most everything.