need information on a warden helmet

Hi everyone, i wonder if someone could shed some light on somethig for me, i have a Warden's helmet which i believe to be from WW2 but after weeks of looking i dont know what the A is for on the top.
Would someone happen to know?
Many thanks.

 

Hello Claire. Would you be able to post a picture or two of the helmet? Thanks much.

 

Hi GearZ, thank you for replying, i did try to upload a couple but it said the file was too big so ill try and do it through my laptop a little later today. Thanks

 

Hi GearZ sorry for the delay, here's a picture of the helmet i hope it helps.
Thanks in advance.

 

HI i just wondered if you had a chance to look at the picture of the helmet or be able to figure out what the A is for?

 

Sorry for the late reply. This particular type of article isn't really in my area of expertise. Shot in the dark: ambulance service? This guide suggests that it is as least possible: