Bob Jones (who else?) does a one-arm handstand on a (tipped) rocker at the York Barbell picnic some time in the late 1930’s (probably 1937). The early York picnics were held right behind Bob Hoffman’s house on Lightner’s Hill in North York, Pennsylvania. Hoffman can be seen bent-pressing the large globe barbell in the background in another picture taken the same day HERE.
They say that the York picnics were so popular that cars were parked three quarters of a mile in every direction. Hoffman’s house is still there and you can see it if you know where to look.