Odd Pattern 1937 webbing; WW2/Post War
First look appears like usual WW2 era Pattern 37 webbing water bottle carrier, but the attachment belt hooks were a surprise to me. The maker mark appears to by the Canadian company of ZL& T Ltd, date is 1943 or 1944. But curiously on one strap is a Nato Stock Number, which looks like 8455-66-013-7640. My understanding "66" is country code for Australia.
My question; is the belt attachment modification WW2 or post war, (as the NSC number suggests) and was this a piece of Australian kit?