Thanks Sheepshanks! I have 2014 Scott edition and, after 15 minutes of checking and re-checking, I could not find a listing for any "syncopated" 67P Machin stamps in the Great Britain section. If you have the SC Number, I would appreciate you sharing it. Thanks!
It looks like Scott has missed this one, it is not in my 2014 either but strangely it does appear on the Steiner pages for 2010.
Maybe someone with a current Scott can give the number.
SG lists the Photo one as Y1735 and the Litho one as Y1788, not that this is much help.
Thanks everyone for your input and help. My old eyes must have been deceiving me on this one. Reading small print is becoming more difficult every year. I
found it in the 2014 Scott as you indicated (MH398).