Back in the 1960s, when the ISWL was thriving, I joined. Subsequently I left and rejoined some years ago. After a few years, I left again. When I left there were about 200 members only. I have no idea of membership numbers now, but I''d be surprised if it was more than 150 and probably far fewer?
Sadly, ISWL was no longer "for me". When I left a few years ago not one email was received saying they were sorry I was going. I was surprised. Every month I had contributed a log, as well as several articles.
My feeling is this is now a very small group that is on the way out. Back in the 1950s and 1960s it was a very strong, international group. No longer do I feel this is true, sadly.
If you are considering joining, then my recommendation is join GQRP Club instead. I have never been disappointed.
See http://www.iswl.org.uk/ .