This is a rare 'childhood memory' stamp. I must have been 7 or 8 years old. It was a summer fete at the 28th Croydon scout group headquarters in Addiscombe and Father best had set up his stamp shop in one of the huts. He had this huge (to me) box of stamps and told me that somewhere in there was a rare Penny Black. I spent hours rummaging through that box to no avail. That a catholic priest would ever lie? Surely not?
I've now discovered that the Penny Black is neither rare (there we tens of millions of them produced and millions still in circulation) or terribly expensive. The letters at the bottom of the stamp (each side of 'one penny') indicate their grid position in the sheet they were printed. Over 50 years since that fete in Addiscombe and it was time to finally bag myself a Penny Black. And it had to have my initials on it natch!