As yet I cannot find a picture of the badge in wear. However it is more likely to be a WOs badge rather than an ORs. As for beret or FSC the jury's out.
However whilst the RUR ORs did wear khaki
GS caps with full sized badges in WW2. It is said that the GS caps were tailored under regtl arrangements to resemble caubeens. The AB Bde ORs wearing full sized badges with green backing on
maroon berets. WOs and Offr wearing the silver AB badge discussed elsewhere.
WW2 officers and
WOs wore green FSC with boss badges.
Post 1954 the
caubeen seems to have been the norm for all ranks. The Queen's Crown North Irish Bde badge was worn on a green caubeen as shown in this
news clip where the Q/C is clear at 1.31 mins. I believe this is the Bn leaving Cyprus in 1959.
However whilst the RUR were in Korea they did indeed wear
berets. They appear to be khaki with a rifle green backing. This soldier has a full sized ORs cap badge. As yet I can't find a picture of an Offr or WO.