The stamp shows the following .....

1. The 7 O'clock ray flaw in the top right corner square.
2. A verticial guide line in the top right corner square.
3. The left side line has been strenghtened.
4. The bottom right corner square has been re-cut.

     The following may also be present .....

1. The top line of the top right corner square may be weak at the left corner.
2. There appears to be traces of a horizontal guide line through the value. (See stamps above).