This album has many of the excellent musicians from Uptown Records.
Frank Wess, Sahib Shihab, Kenny Barron, Jack Sheldon, Carl Fontana, Al Cohn, Barry Harris
Tommy Flanagan, Richard Wyands etc.
A very lengthy list, but I was only familiar with a very small percentage of them.
I would estimate that there were only about 15 jazz musicians and maybe 7 or 8 classical musicians on the list.
The closest I could find were these two. Though not the exact same line up of musicians as in the photo.
JATP In London 1966 - Pablo
JATP All Stars - Pablo