This is what Bill posted on Facebook a couple of days ago:
Derry was a very important part of the Mersey scene and a good friend of mine. Derry & the Seniors were the very first Mersey group to go to Hamburg and the first Mersey group to make an album and single. There were two lead vocalists during their Kaiserkeller season - Derry and Billy Hughes. Derry was the ultimate showman and he was the one Koschmider referred to when he told the Beatles to 'mach shau' like Derry. At one point Derry gave up singing, but i encouraged him to form another group. He and I were going to collaborate on a book about his intriguing life called 'Black Scouse', but he vanished from the scene for years, disappearing in Italy where, I think, he had a jail sentence. I then saw him again in London at the Cromwellian club. Derry had a few too many, went out of the club, stole a bike and crashed into a police car at a set of traffic lights. Going up the escalator at Baker Street Station, he was going down and shouted out 'Bill, we've got to get together for a bevvy." I never saw him again and he passed away at too early an age.