I've never been a fan of Aussie Merlot. I agree, it has a flavour profile of wet cardboard.
But I remember going to a DWS trade show in Brisbane in 2012 (how I remember going I don't know, I ended up ratshit drunk) and sat in a few of their master classes. One was for Bordeaux, and got the shock of my life. I swore blind that I was drinking a 100% Cabernet Sauvignon, only to be told I was drinking a wine made up of 98% Merlot and 2% Cab Franc.
SGL / Baz - any good tips on where to find a straight Mourvèdre?