The W-Nikkor 1:2.5 f=3.5cm I bought new in 1953 lines up on my Leica adapter much like your Nikkor on your Fotodiox adapter. A critical dimension for proper viewfinder frames is the face of the mount locking lug about 45 degrees counterclockwise from your thumb in the photo. That face operates the frame selector switch, and a little error makes all the difference. Too many items from overseas are made by people who don't completely understand the function of the item, or are meeting a low price instead of making a precise product. I've bought too many spring clothespins made in Chine where the maker didn't understand something that simple, or didn't care.