Are the M.O.H. ARP Lamps Wartime Or Not?

Seeking to draw on the power of the information superhighway, I'm trying to finally get to the bottom of the issue surrounding the hooded ARP lamps with the label:

LAMP A.R.P.
with Hood
M.O.H. Code No. WD 3051
​M.O.H. Order No. S1/52/B1

On a forum I read many moons ago (and which I cannot currently locate online) someone commented that the M.O.H. designation was a post-war designation. Can anyone confirm or deny this?

UPDATE: a number of people responded to this question on Facebook. Currently the consensus points to these being post-war lamps.

Lamp A.R.P. with Hood