WW1 Brodie Helmet Great Britain

Why are there no comprehensive books on the British Made WWI (World War One) Brodie Helmet?

This helmet had several variations and of course evolved during the course of the Second world War.

The Brodie helmet probably saw some of the most violent fighting in the 20th century and is extremely collectable in original format. It was also used by the USA in WWI and they went on and developed their own version.

The American versions are covered very well mainly in the 'Steel Pots' book by Chris Arnold.

However that British book on WW1 helmets seems to be a huge gap in the helmet collecting market.