Just in case anyone's looking for one, Hero Outdoors sold me a large for $19.99
http://www.herooutdoors.com/canadian...et-cover-used/
It was fairly faded and had one large (patched and sewn) tear - I'd rate it 4/10 for condition, but it was the real deal, proper tags and with the fold-out neck cover (which I didn't even know was a thing). I got it two business days after I ordered it on the weekend.
It fits quite well on my repro MICH 2000 helmet, which I also managed to source!
It's funny to compare the original colour of the unfaded (and obviously seldom or never used) neck cover and the weathered helmet cover - very different!