Hello ThePete,
Concur, HSAT MkI. Judging from thickness of inner foam liner, probable small size. Nice helmet, excellent condition. Early leather chin harness. May want to glance at
http://arnhemjim.blogspot.com/2015/0...e-helmets.html . Conjecture, other flag possibly British Commonwealth (Shield scraped off, possibly Canada?). Rampant lion open to question. Worn by exchange personnel?
Arnhem Jim Aka Arnhemjim
Arizona Territory