Ron
You can also see this mark in Robertson Ship letters and the follow up Robertson Revisited by Tabeart. This is indexed as N1 in use 1937-38. Double circle with thick arcs.

Hi
Can anyone help me plate this penny red please. As hard as I try I never seem to be able to accurately plate any.

Perf 16 small crown :

Dear All

I have been rummaging lately and came a QV 2½d Jubilee issue stamp with a single rim CDS - BRITISH POST OFFICE CONSTANTINOPLE, dated MY 27 94.
However I couldn't find it listed in the SG Specialised. Would be Z149 if listed.

Can anyone shed any light please.
Thanks
Steve