The full body harmonica rack might aslo be a clue as to where and when the shot was taken. I've not seen one of those anywhere before and always assumed that the neck rack was the only style ever made. I'm assuming that the shot was taken somewhere in the deep south, maybe New Orleans or possibly Memphis, but could be from anywhere.

The guy looks well fed and fit and his hands are no strangers to hard work. He may not even have been a musician at all, but only had his photo taken with the props like they do nowadays at the state and county fairs' midways.

Notice the guitar is seemingly strung upside down. I learned from the pre-war blues list that this is due to tin types reversal of images, so the photographer would have guitar players etc. hold their instruments "left-handed" so as to make them appear right handed in the final product.