dj-magic, I've been through the same thing myself here down under, I have a 2012 Boulevard M50/VZ800.
The 2010 model had a new rear fender design plus the M109 type headlight shroud. 2009 and before had that ducks arse rear mudguard and the mounting points were exactly the same as the C50/VL800 - parallel and 212 mm centre to centre (I've seen it quoted as 2 1/2 inches, that's close enough to 212 mm).
The 2010 onwards M50s/VZ800s had tapered mounting points and 200 mm bolt centres. I had side plates cut out of 6 mm aluminium to mount my top box and saddlebags and to run them parallel I had to pack out the rear mounting point by about 30 mm or so (I think the exact measurement was the thickness of 14 x 8 mm washers).
Because there aren't that many post-2010 M50/VZ800s around, there isn't a lot of aftermarket fittings to match the new bolt centres and tapered layout, either from Suzuki itself or from aftermarket manufacturers.
So, while you have a different bolt hole centre, do keep it in mind that the mounting points are tapered in towards the rear as well.