In Hicks book he has a list of the guys receiving long service awards. The (other ranks) medal they would have received is shown below. Never seen one to the 2nd Northumberland AVC, but that is to be expected looking at how short that medal roll is! (but I've just been looking for 40 years, so there is time yet.) I do know a dealer with one to the 1st Northumberland AVC (Tynemouth) though.
I see our Warkworth brewer Henry Lamb received one of these but handed it back in in exchange for the officers' type decoration when he got promoted.