Thai post issued a stamp to commemorate the 130th anniversary of Thai Postal Services. This issue consists of a single stamp featuring a "stamp on stamp" design, linking the beginning of the Thai postal service in 1883 with the modern day.
The featured stamp in the design is the 1 solot stamp from the first Thai stamp issue, the so-called Solot Issue. This stamp is listed as No.1 in the Somchai Saeng-Ngern catalogue. It was issued on 4th August 1883, along with 4 other values. The 1 solot stamp features a profile of His Majesty King Chulalongkorn (Rama V), under whose reign the Thai postal service was established.
Although this is an iconic stamp in the Thai postal service, it is not too hard for a stamp collector to find it for purchase, nor is it prohibitively expensive to obtain a used version.