The Ceylon cds exists in 2 forms. The wide spacing in the letters CEYLON,and the narrow spacing in Ceylon.The wide spacing type Ceylon can be found on QE stamps. The narrow spacing in the letters CEYLON can be found on KGVI & QE stamps.
Below the OP's stamp. The green line in the upper portion seems to have been washed away.The lines formed a cross over the stamp (& document).The OP's stamp has the wide spacing CEYLON cds.
The washed out portion is visible and apparent in the photo.
The question most essential is the following: When were the wide spacing CEYLON cds types first used ?