I read that Stan Tracey and he didn't get on at all during a mid 60s Ronnie Scott stint. Lots of nasty messages passing from the horn to the rhythmn section apparently. Same thing seems to have happened with Don Byas. Stan was a very supportive and supremely adaptable musician who backed all of the US visitors to the club so odd that this was the case.
With regard to that European sojourn, there was that attempt to put together a Lucky Thompson conference here in the UK back in the 1960s, which Lucky mentions on that message at the start of the Candid CD. Never happened in the end..