Costa Rica 1926 5c General Post Office, SPECIMEN overprint with small punched hole, there is a pencil number on the gum of "1/29" which I believe is the date of the printing, from American Banknote archives. (Scott no. 121) The stamp is o.g. NH.

U.S. buyers free shipping, $1.60 to foreign addresses (no additional postage increase for multiple lots purchased same day, please use shopping cart when making multiple purchases from my store). Registration is $21.00 additional and it may be required to certain countries where we have had losses, please inquire. We do NOT ship to any countries of the RUSSIAN FEDERATION or to GERMANY. Shipping to Taiwan and South America only by registered mail. Shipments of $15.00 or more to Austria or Italy must be sent by registered mail. Please wait for invoice after auction sales.