The latest Record Collector Magazine (April 2011) had another gemm to show. On their ‘Most wanted’ pages they a picture of a 1965 folk-concert flyer. It’s the January 29th ‘All Star Folksong Concert’ which shows the names of Martin Carthy, Paul Simon, Dorris Henderson and Martin Winsor. The concert took place in London’s ‘The City Temple Hall’.
I had the date already mentioned in the 1965 section, but here’s a picture to make it complete:

