Regional Column Mk2

A hard to find Regional column marked Mk2, these were reserve units that were formed in 1940 & were to assist where needed most. If an area was overwhelmed by an extra heavy raid & the local force was not coping the Regional column was called in by the regional Commissioner hence Regional Column.
They were a self contained unit of about 200 strong & consisted of Rescue, 1st Aid, Ambulance & Decontamination, in 1941 they became established under the control of the Regional Commissioners & known as Regional Columns.
By 1943 there were 14 such units.
I think the helmet was once a First Aid marked helmet as there is a large circle under the paint at the rear, which makes sense if he joined this unit.
The shell with 1 hole in the brim No.2A is dated 1941, the liner by BMB dated 1940 & with a nice ink stamp of O.K BB No7 on the khaki cotton liner.