[ad_1] The classic metal lunchbox with thermos flask was once standard issue for the country’s workforce and school children alike. However, the introduction of vinyl (PVC) led manufacturers to switch away from metal as their primary manufacturing material. There is now a growing interest among collectors (and pure nostalgia junkies!) in vintage metal lunch boxes and their accompanying thermos flasks. Unfortunately, the resources currently available on the web are fairly limited. Here is a short guide on how to find…