Among blues and jazz musicians and probably others there has often been a "wicked"? sense of mischief. Pouring soapy water or some talc into the bell of a saxophone for example, adding a very small bag of sand daily into the F holes of the double bass until eventually the bass player complains he must be getting weaker, de-tuning a guitar etc. It all helped to relieve the boredom of life on the road with the same bunch for company. However I doubt that anybody would try pulling the same trick for forty years.
Personally I never saw Sonny using a bandolier, just various pockets.