This is similar in design to the 1889 $25 revenue but is inscribed at the top with "the state of". They are not listed in a normal stamp catalogue as they were used purely used for fiscal purposes eg in land deed transfers, court fees etc and were not eligible for postal usage.
Multiples of this 1894 issue are not uncommon. Complete sheets CTO with the 14 bar cancellation are occasionally seen. It was lithographed by Blades, East and Blades of London in sheets of 5x4 and perforated 14.
In contrast to the 1889 issue, it was thought no die proofs are in existence. However, one in light olive brown is present in the collection of a senior member of the Sarawak Specialist Society. The above item is in a lighter shade printed on a smoother and thinner paper. It is an imperf plate proof. The differences between a plate and a die proof can be confusing. The main difference is a plate proof is part of a sheet and may existence in multiples whereas a die proof is printed singularly using the original die in an initial printing to test the integrity of the printing plate.
This item is more uncommon and should be more valuable than the many perf CTO copies which are available. A single or multiple mint copy would be quite a coup.
This is an uncommon variety which has been hand stamped Specimen. Specimen sets of postal stamps exist because there was a requirement to send copies to the Universal Postal Union headquarters in Berne, Switzerland from where it was distributed to member countries.
Revenue stamps are not postal and so specimen items should not exist. It has been postulated that these adhesives were locally hand stamped before they were given as souvenirs to important visitors. It was a measure to prevent subsequent fraudulent use which would have deprived the treasury of revenue. I have a similar version on a 1894 25c adhesive. They are generally uncommon and worth collecting.
The above stamp made my recent holiday trip really worthwhile. Properly used items are quite rare that it was my immense good fortune and perhaps once in a lifetime experience to have the privilege to acquire it at such a reasonable price. I have yet to decipher the fiscal cancellation. It was perforated JUDICIAL and therefore was used in a legal situation. It was originally part of a document and very very few documents like that exist intact nowadays.