The so-called Missing Die forgeries of the Circulars of Jammu & Kashmir are ubiquitous - well, a lot more common than the genuine stamps
They were supplied from the Jammu & Kashmir Post Office with supplies of genuine types, so were for some time thought to be 'missing' dies. Their true nature was revealed some time after they appeared and began infiltrating collections. It appears crooked officials of the State Post Office saw a way of supplementing their incomes by printing imitations of the genuine stamps, and inserting them into the official supplies.
Here are some examples of the Missing Dies and genuine stamps:
First the ˝ Anna type:

The Missing Die is on the left. The two simplest diagnostics are that the leftmost line in the central circle touches the frame of the circle, and the bottom of the letter shaped a little like a '3' immediately above it is curved around to the left, and touches the letter next to it.
The 1 Anna type:

Here, the Missing Die is on the
right. The simplest test is to draw a line from the upright line in the central circle. In the genuine types, the line passes between the two letters above it; in the Missing Dies, it points directly at one letter.
The 4 Annas type:

The Missing Die is back on the
left hand side. The test is the same as for the 1 Anna value. In the genuine types, the line passes between the letters; in the Missing Die, the line passes straight through a letter.
The Missing Dies aren't the only forgeries of these stamps - just probably the most common. There are also reprints (sometimes quite hard to pick) and 'non-postal' types, which while apparently genuine, never actually saw postal service, and were simply post office experiments

If that hasn't frightened you away from these fascinating stamps, I can heartily recommend them as a study
