This photo still exists, I do not know where it is. Brad Wood, the Case hunting knife expert has seen it and the obvious tang stamps. I believe Katie Shontz, Case factory historian is aware of the tested xx marked WW2 pocket knives made for the military. I will see if I can get a copy of it, but may not be able to get a good high-res copy. It is thought by some advanced researchers that the Case Tested XX mark on pocket knives was not discontinued until after the war, maybe as late as 1948. The first CASE XX mark we know for sure seems to be used on a knife/axe combo with interchangeable blades circa 1937. There were fixed blade knives made at that time with CASE (serifs) marks and the first CASE XX fixed blade with a definite time frame was the later war CASE XX marked military quartermaster fixed blade knife which was also issued early in the war just marked CASE. The WW2 bailout bolos also wore the CASE XX mark, but there is not yet a definite date association positively provable for this mark on pocket knives. Case fixed blade knives have always had different markings at different times from their folding knife brothers in most of the Case manufacturing eras.