OK, I apologize! One for being tardy, and one for having a spotty memory. When your collection is 150 ft. from your computer, you tend to slip on numbers. While I have been being tardy, the discussion has added another case length, the 42 X 184.
So, I went out to check things out, and instead of having the 42 X 153 in Nordenfelt, I have the 42 X 260R, and the 42 X 184R ( I had rounded it up to 185). Since these are 1.65 inch, I checked my U.S. turn of the century 1.65 inch gun rounds, and they are 153mm long. Since the U.S. copied everyone else's calibers back then, is the 42 X 153 Nordenfelt the same as the U.S. 1.65 inch gun case?
I will post a photo of all three together.