Found at last...
A piece of guitar-based library music, sometimes heard on Pathé News items of the mid-1960s.
Irritatingly familiar, yet never identified... until today (courtesy of the Shazam app on my iPhone - I don't know why I didn't think of that before).
Dine And Dance, variously credited to "The Scottmen" and "John Scott" for performance and (of course) just to John Scott as composer. John (often referred to as "Johnny") wrote lots of library music, including The Good Word (the theme from BBC TV's Nationwide) and was a noted saxophonist and flautist in almost every famous recording and broadcasting band of the 1960s. He made a side-career of sounding just like Paul Desmond (of the Dave Brubeck Quartet) on alto sax.
Anyway... does it ring a bell with anyone else? I cannot say how pleased I am to final ID this recording and to hear it all the way through. And are those roundwound bass strings? Maybe Rotosound Tru-Bass (the black nylon tape-wound bass strings)?
https://clyp.it/unw4llpz