DOES ANYONE HAVE ANY TIPS FOR TESTING OLD PAPER TO SEE IF IT WAS REALLY ISSUED IN THE 40'S OR FIFTIES? I'VE NEVER GOTTEN ANY BAD STAMPS AT STAMPWANTS, GOT ONE FROM EBAY YEARS AGO, CONFEDERATE ISSUE. I SCAN THE MAJOR STAMP SITES DAILY AND HAVE NOTICED A LOT OF OLD, EXPENSIVE SOUVENIR SHEETS POPPING UP. I KNOW ITS DIFFICULT TO REPRODUCE 50 YR. OLD, YELLOWED GUM, BUT WHEN ADVERTISED W/NO GUM, I CAN'T REALLY BE SURE W/O PROFESSIONAL ATTESTING.