WWI British MkI Brodie Helmet Restoration

[peregrinvs]

How can you tell the difference between a rimmed MK1 or MK1* helmet shell of WW1 vintage and a MK2 shell of WW2 vintage, ignoring any liner which may or may not be present?

Massively summarising... there are various differences in the shell shape, chinstrap attachments and stamped maker marks. The earliest helmets also lacked a steel rim protector. In the case of the markings, WWI British helmets tend to be marked with 2-3 letter initials followed by a 2-3 digit batch number. WWII helmets tend to have both maker marks and the year of manufacture. I suggest you have a browse through here:

Military - Britain - The Brodie Helmet and its derivatives