I found the auction listing for this item. I believe the stamp to be genuine, but beware of the hype in the writeup:
Quote:
United States -- Scott #R33a mint and scarce Certificate revenue stamp First issue revenue stamp. Mint no gum. All mint first issues command a premium. Huge side margins with part of adjacent stamp showing at right. A beautiful stamp and ideal addition to any quality collection.
Without gum it is not mint. It is merely uncanceled. Revenues are not treated the same way as front-of-book material.
For 1st-3rd issue revenues to be considered "mint" or "unused" they must have gum. The company is correct in that "mint first issues command a premium", but this isn't one.
Still, for those that collect 1st issue revenues free of heavy, marring, or distracting cancels, this would be a nice example.