As you think the answer is yes the NDTSG is a national section that is called in to support operations in all Gaol’s when required.
Also as Destro pointed out Stars were used previously to currant rank badges to denote Rank but bar’s were also used back in the 1960-70’s for the same thing post the Mountbatten review.
Re inventing the wheel!
These are the old & new style bars, worn only on Dress uniform today.
See here
https://www.britishbadgeforum.com/fo...p?albumid=3400
Regards
Stephen