Fascinating. I shall now have to examine thousands of photographs for evidence !

The November 1939 dated KG No.3 Jaeger clock with cable that Jan acquired in France had no rivet and no cable security device (it would be difficult with the Jaeger top fitting tooo) so this must have been a later-war introduction.

My CVC box did have the lock-wire still in place...was that to stop them from stealing electricity ?