Many thanks for your response Martin. I have made some progress since my original posting, having acquired copies of 'Numbered Postmarks of Scotland 1' & 'Experimental Duplex Cancellations of Scotland' produced by The Scottish Postmark Group. The B5 category really only specifies a duplex with t...

I am endeavouring to group my accumulation of Edinburgh 131 duplexes (excluding dotted circles and Brunswick) according to font characteristics, number and length of bars, style of any stars, St Andrews cross cuts and suchlike. I am aware that much has been written on the subject but need help with ...