Note the 9th edition can be found with 2 slightly different covers one has GP83 to the Spine, the one featured on this page has X233 to spine.
9th printing 1963. Pan X233 to spine. Copies have been found with :
10th printing 1963. Pan X233 to spine. Copies have been found unpriced and with 3’6 printed to front cover.
11th Printing 1963. Pan X233 to spine. Copies have been found with 3’6 printed to front cover.
Note the 11th printing can be found with this artwork, but is more common with the “Hawkey” designed artwork. As multiple copies have been found with both artworks it is assumed this is a transitional printing where excess covers from the earlier printings were used up.