The Beat Club stuff sounds most interesting. There person who might know is Colin Harper who I am sure would have looked into any John McLaughlin performances. If not then I'm sure he knows. There is a very good interview with Michael Leckebusch of Beat Club in the seminal book Vox Pop by Michael Wale pub Harrap in 1972. He seemed then a very committed individual who blazed a trail for getting this kind of music onto the mainstream media. Perhaps this is the reason why Europe got it better than the US and UK - or so my imagination tells me.