The red army faction really wasn't very big in Britain. Neither was the red brigades.
The IRA was pretty big in the UK. So was the NUM, albeit in a very different way.
It was the murderous bombing of Libya by The Empire, from imperial 'owned' airbases in England that triggered Gaddaffi's support for the Republicans and that union. Prior to, and subsequent to that support, the principal support for Republican terrorism came from the US.
The LaBelle disco thing was nothing to do with Britain, or Libya for that matter. It killed a Black NCO and a couple of Turkish hookers, but that was done by Syria, not Libya.