Here's some detail pictures of the late issue hat which is the same as RMET one. You can see that the guide holes are part of the mould but a rivet has never been put in. If a rivet has been removed from an Australian hat to pass off as one of these it is usually obvious.
I know, a late contribution : I've read that the M1 with plastic strap turned out to be hard to come by. What are your experiences ?
A late response I know. I've found it an absolute sod to find. I'm sure it was you I bought a lovely late set off a year or two back with a glued rifle that you had told me about before the sale. I only managed to find a replacement around Christmas time but it was cheap. I think its one of those hard to find but low value items.