Finally back to follow up on this post. As already stated, I have a Ridgeback Cooler King. I bought it back in 1998 for ~£400. The only things I've changed since new are new front brake disc & calipers and the rear tyre.
It's still going strong; I did Bath to Reading on it a couple of years ago and it was fault free. These days it's a bit like riding on an old sofa.
Link to muddy image during Bath to Reading:
https://photos.app.goo.gl/Wr2y3b1gkw5gkHoe9Another on Caversham Bridge for the Kris Jarvis memorial ride:
https://photos.app.goo.gl/2rhJeS8BGux1gSLfA