My oldest Instruction is from 1940 – in 1941 and the difference to the predecessor ( not in my possession) can you find in "Zippo Fluid and Flints". In the Instruction from 1939 –1940 is a pic from a petrol bottle and a package with flints, this was removed in 1940. And you could buy a bottle for $0.25 or a cardboard with 12 bottles for $3.00
The instruction from 1942 - 1945 was only for Black Crackle Zippos and had no information about bottles, flints or engraving needs. In this instruction is only a information how you can fill the Insert.
Between 1946 and 1947 there was again a "complete" instruction. You could buy engraves, flints and fuel bottles and a cardboard with 24 bottles cost $6.00. However, the Barcroft and the Gift Set is not available. A stamp with the words "Not Avaiable at present" was on the picture from the Barcroft and the Gift Set. The designs in the 2 years were "Scotty" and "Drunk".
In 1948 there was a further instruction. The Barcroft and the gift set have been completely removed and the motives have changed. Now they could choose between "Dog" and "Drunk".