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Quote:
question regarding "U.S. first issues" from the 50's and 60's
"first issues" could mean a lot of different things to different people. It's not the first US postage stamps because they came out in the 1840s. First issue also refers to the first set of US Revenues, but those came out in the 1860s. So at this point, I'm not really sure what the dealer is referring to.
You will need a better description from the seller (what kind of stamps -- postage stamps, revenues stamps...) and an explanation of what is meant by their usage of "first issues".

Kim