Hi Nigel,
I would not consider myself an "Expert" but I have been collecting for
many years, although I have no contact to other philatelists and have
been happy to go my merry way the last 20 years in full isolation.
In fact most of my catalogues are as old as the stamps themselves!
Michel Briefmarken Katalog Band I Europa 1923.
Senfs illustrieter Breifmarken Katalog Europa 1942.
I also have a lot of old reference publications and feel it is a shame that
some of the information is no longer available to modern philatelists.
Cheers, William.