Mathew
Yes - I have masses of recordings of Ewan's classes - too many to get organised, truth be told.
If you let me have an e-mail address I am happy to pass some on via Dropbox.
As you're a non-member, best ask Joe Offer - he has been kind enough to help before.
Pat and I did two, hour-long obituary programmes on Ewan a couple of years ago which featured Ewan in teaching mode - it gives some idea of how he did things - happy to send copies of those to whoever wants them
There were several offshoots of The Critics Group down the years; I ran one in Manchester in the sixties before I moved to London, there was a long running one in Birmingham which eventually evolved into Banner Theatre, several dotted around England and Scotland....
When the Critics broke up, London Singers Workshop evolved and ran for fifteen years
These workshops are easy to set up and extremely effective - it only takes half-a dozen (or less) like-minded people who are prepared to work on each others singing in an analytical and friendly way
Let me know
Best
Jim Carroll