It is not too difficult to find originals of the Seebeck postage due stamps of El Salvador although many reprints are on the market.
In addition, it is not too difficult to distinguish between an original and a reprint once you have seen a number of originals. Almost all of the reprints have a muddy appearance while the originals are crisp and clean. Shown here is an example of each.
There are also a number of counterfeits on the market but if you can tell the difference between a lithograph (counterfeit) and an engraved (original) stamp they should not fool you.
Finding unquestionably genuine cancels on the postage dues of the Seebeck period is extremely difficult as most cancelled copies have been favor cancelled or had counterfeit cancels applied to them
Obtaining Seebeck era postage dues on legitimate covers is next to impossible, as only TWO covers are known. Shown here is another gem that was in the Bill Welch collection.
22 centavos charged on unpaid letter from the U.S. The 25 centimes was equal to 5 cents, the U.S. rate to El Salvador.