Cromwell made these protector helmets for the general public to buy for there own protection, this one is called Bentafex protector helmet. So I'm not sure if Bentalls have purchased these helmets from Cromwell & put there own labels in to sell through there store, or have had there own ones made.
Have seen 3 types of chin straps with these helmets so far, this one, the normal MkII chin strap plus one which looks like it is made from the same material as the liner.
The two I've got are not dated, they just have the size.
Please show yours if you have one to compare.
Bentalls the store are still going today.