well BP, went to my junk box and found two film reels that would hold rollfilm that fits that reel. They are both the same length, just larger. The bigger wooden one is 116 and the thinner metal one 616. These are Kodak #'s. The cameras that they fit, at least the ones I have are a mid to late 20's autographic, the Brownie box and that handsome folder probably from the 30's to early 40's. ..so quite likely your dad would have processed this film size either from one of his own cameras or from one of his friends.