Royal Navy formation badge ?

[Markus Bodeux]

Hello all,
i have got this badge together within a lot of RN WW2 trade and rank badges.
It shows a machine embroidered yellow/golden dragon with some red applications in his claws, on dark blue cloth. The reverse is backed with a thin black fleece. Worn and removed from an uniform.
The outer dimensions are 105mm height and 90mm width, i would say a large sleeve badge.
Any idea what it is ?
Thanks for any comments and help,
kind regards
Markus