This helmet was first posted in the M1s of 2014 thread, and it was requested that I post more in depth photos. So here it is, an early fixed bale modified with the addition of a "Swivel" bale from a mess kit. These were designed to replace the M2 helmet, but the modification was found to compromise the integrity of the shell. This modification did eventually lead to the M1C.
This particular example is missing most of its paint and is rather rusty, but is a representative of a very hard to find helmet.
(This link goes to another discussion on this forum about this type of helmet eBay M1. Unusual Claims)