The first proper despatch rides helmets were first introduced in 1939, the Helmet, Crash, Despatch Riders ( HCDR) Before this they would have used soft caps, MkII steel helmet or leather helmets similar to pilots helmets which would have kept them warm but would have given no protection.
Being made of rag pulp within layers of linen & coated in shellac varnish. In 1941 a modification was added, 2 extra ribs to protect the lace that went around the helmet which held the liner in place.
This one has seen better days & had a hard life post war, being painted many colours. It is dated 1942 & made by C.C.L, it also has had the flaps taken off which cover the ear vents.