Impossible to find m1918 style chinstrap. This is the combat model
and not the lighter style strap commonly found on pre-WWII helmets.
Flat aluminum or steel buckle with all steel wire fittings and sewn with linen thread.
This chinstrap will have to be sewn onto your m18 liner d-rings using the
pre-punched holes and the linen thread provided.
A hard to find item at a reasonable price.