The podcast The RFK Tapes might pique your interest. Not European but some very interesting incongruous circumstances.

Have you read Reclaiming History: The Assassination of President John F. Kennedy by Vincent Bugliosi? It’s massive, but I’m working my way though it at the moment and it’s really good. I’m still not convinced that a SS agent didn’t accidentally shot JFK in the confusion, but Bugliosi goes through the timeline and all the attendant conspiracies in great detail.