I actually sold Martin that copy, it was a Parlophone issue, have to say it's the only one I've ever seen, having said that, I had a demo in my own collection a few years ago and I haven't seen another one since...I sold the demo for £25 in 1993...I was offered £150 for the issue so I thought I had no choice but to take it. I'd think it's real value is maybe £100, might be wrong, definitely a rare item though, and it's absolutely brilliant. The Val Simpson I think is ok but totally lifeless without brass, and a lot slower.
I'm sure there's some link between John Andrews and the group Supertramp