An update from Alan by email:
It was definitely not a Jay, nor a Jackdaw, I know my birds fairly well but have never seen anything like this one before.
So, I have drawn it for you and your members. I'm no artist so - sorry that my redwing resembles a duck billed platypus. The drawing should be mainly used for colouration clues although my mystery bird does look a bit more like what I saw than the redwing does.
Thanks for your help.
(Drawing attached to topic heading)