Help with early MKIV helmet insignia

[Jimir]

Hi guys
Picked this up last night at a local auction, it came with a 1945 marked Demob suitcase.
It’s an early MKIV stamped RO CO FB 4 1945 with a Mk3 liner, C&L 111 1945 and a MK4 chinstrap.

The inside is brown while the outside appears dark green.

On the right hand side is an upside down red triangle. Does anyone have any idea what it signifies? Could it relate to the Coldstream Guards.

Any help would be greatly appreciated
Chris

[Jimir]

Here’s a close up of the insignia

[tinlid]

During the war yes, but I can't say for sure this is for the CG post war.

[Jimir]

Thanks Tinlid
I bid online expecting to get a 50’s MKIV. When I picked it up this morning I was very pleased to find out it was an early MKIV