Where is Inverted Jenny 66? There are just 100 of the world's most famous error stamp, printed in 1918 with an upside down plane. They include four called the McCoy Block that were stolen from a show in 1955. The McCoy in question was Ethel McCoy, who was the daughter of one of the founders of the Dow Jones company and a keen and celebrated stamp collector. Three of Mrs McCoy's stamps have resurfaced, the most recent in 2016 thanks to the FBI. But the top-right stamp, position 66 on the sheet of 100 Jennys, is still out there somewhere. Keep your eyes peeled!

@Darren Knight I can't find my old CP catalogue (clearly there's more cleaning up to be done!). Would you be able to do a lookup for me when you have time please? This is 1916 2d Yellow, SG418, and there's a colour spur in the top left corner, and I'm wondering if it's a listed variety. Any help greatly appreciated!

This is a prime example of "value confusion" that new collectors have to wrap their heads around. These are quite obscure stamps, issued for the Russian PO's in Turkish Empire 1868-1879, and are the first ones I've handled. They're not something that dealers see every day. The catalogue value for this group is only £24. A classic example showing that old doesn't equate to valuable. They're attractive and would be a nice thing to have, but definitely not investment-worthy.

There's some eyebrow-raising numbers and some excellent advice in this article https://www.justcollecting.com/blogs/news/top-10-tips-the-1m-rare-collectibles-of-tomorrow

A change is as good as a holiday (daft analogy, no it's not. Holidays are MUCH better), but the new persona is a much more accurate representation of who we are.