Well, isn't ONE of the VP160 sides at a 90 degree angle to the front? i.e. if you shim the top flat, won't the front be plumb? That's how my VP100 was.
I know, it would probably SOUND better with a bit of an upward tilt (as designed), but it might be an acceptable compromise to get all the pieces to fit together.
I was actually considering buying an in-cabinet VP180 so that the top and bottom would be square and make it easier to use as a stand. Axiom seems to finish the in-cabinet version box with some decent-looking black melamine (or such).
But I'm not spending money on that stuff right now.
bibere usque ad hilaritatem