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I am a collector of United States postage stamps, and also a stamp dealer. I`m a member of the American Philatelic Society (APS). My principle area of interest and expertise is in United States Stamps.

Experience in the area

I've been selling stamps on the internet since early 1996. I maintain a stamp web page that concentrates on mint US stamps issued generally between 1890 and 2009. I'm an active seller on since 1996, under the user id "mleon". You can find my web page at


I have a Bachelor of Science degree in computer science from the University of Nevada at Las Vegas, 1984.

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    K = Knowledgeability    C = Clarity of Response    P = Politeness
Elizabeth12/09/16101010Thank you for your time.
BRIAN11/03/16101010Everyone says to buy what you like .....
Richard10/23/16101010Thank you, Mark. I didn't find this .....

Recent Answers from Mark Leon

2017-01-10 Jefferson Memoriual Booklet:

RP,    That's puzzling.  When I think of frameline, I imagine a thin line surrounding the design, which does not exist on the 1973 Jefferson Memorial issue.  Even the booklet covers have a solid background

2017-01-10 MLB Plate stamps:

Janella,    My expertise is limited to United States stamps only, so I cannot speculate on the resale value of your Grenada issues.  I've never heard of the International Collectors Society, but I suspect

2016-12-16 13 cent preprinted postage envelopes Bicentennial:

Andy,    Unfortunately, stamps from the 1970's have not appreciated in value, and most sell for below face value in quantity.  The stamped envelopes you describe, called postal stationery, are still valid

2016-12-14 scott 596?:

Senthil,    Note that 596 is perforated gauge 11, which is not the perforation count on each side, rather it is the number of perforations within two centimeters.  My guess is that the stamp pictured is

2016-12-12 lunch wagon1890s stamp:

SARAHI,    Definitive issues like the 1991 Lunch Wagon were issued in the many hundreds of thousands.  So many exist that they have not appreciated much in value.  If unused with full gum on the back,


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