I have a V35, and I checked it last night to see if the projected image is centred. On mine, it is. Did you assemble the enlarger from the box? If not, I would check through the assembly procedure in the manual to make sure it has been done properly. I agree that there is no obvious adjustment available for alignment. I also agree that there is little scope for play in the negative stage or holder. The lamp points horizontally, so I can't see it being the problem. The mixing box is easy to locate so shouldn't cause a problem. The masking blades are prone to breaking. One of mine has stopped moving, but is not in the light path. You should check that the blades are fully retracting, and not stopping whilst still in the light path. A possible cause could be the column tilting slightly to one side. You could possibly check that with a plumb line.
I hope you get it fixed. It's a great enlarger. I've used mine non-stop since I got it in 2010.
Alex.