One of the things I dearly love about the modern era is the popularization of niche hobbies. No matter how obscure your interest might be there's bound to be someone that shares it. Propnomicon itself is a good example.
What's even cooler is when one of those niche hobbies overlaps your own. I'm only vaguely aware of vintage radio collecting, but these vintage battery label reproductions from Radiola Guy are right up my alley. Need an absolutely authentic battery from the 1920s for a prop project? Take your pick of labels for making your own, or order a fully functional battery. He even has a step by step tutorial for making prop batteries using an off the shelf mailing tube.