I have the same Voigtlander adapter and the 15mm Heliar in LTM and I have the same issue with the adapter and the lens, in that the center points won't line up.
They were out by about 5 degrees as I installed the lens with the adapter on my Leica Ms. When I installed the lens on my iiif it was out the same amount in the other direction.
I was a little concerned, at first, that the built in hood wings would cause vignetting, but that didn't happen. The problem is only aesthetic.
I found a partial solution, that seems to work just fine:
-On the base of the Heliar are 4 screws. Remove the screws and remove the LTM base.
-You then will find there are about 5 threaded holes assigned to the 4 screws on the main part of the lens.
-Realign the base to accommodate the adapter and the center lines of the camera. I had to use the very last set of holes on mine.
Of course this won't work on a Leica lens and maybe only on the Heliar. The lens is badly out of align on my iiif unless I align the lens base to accommodate the