Australian Rimless Mk II

I have had this Aussie Rimless Mk II in my collection for some time now and they are very hard to source it is one of my all time favourites as it shows hard use and IMO was field worn in a theatre of operations.
It is a we bit of a Mystery helmet as there is no makers mark in the form of a stamp on the helmet body the liner is with out a doubt Australian produced and was manufactured by Dunlop Rubber Co...and it nicely shows the size, Broad arrow mark and the inspectors initials not all examples of Australian WW II Mk II helmets are marked with the CS batch number...
I am happy to have it in my collection as a period worn original I carefully scraped a little paint of of one of the lugs with my fingernail and found they were indeed stamped as 1940 Mk II's so this does help to narrow down the production date.
There is some wonderful period Graffiti carved in the textured paint all the way around the helmet five different phrases and statements as best I can tell and IMO done along time ago do to the wear and patina which has obliterated some of it and it is now lost to the ages.
(AUSTRALIAN LAST HOPE) ( IX ) ( MD )( FISH )( KILL KID )
The only stamps that I can truly make out are on the interior of the helmet body near the rear edge of the rim the number 89 is lightly stamped in the steel and it looks like there are a couple of letters as well but it is near impossible to make them out.

Regards Mark