Gorgeous lens - I didn't even know it existed! But I am surprised to hear you talk of several 1950's era Japanese super speed LTM lenses, and NOT mention the Canon offerings, both the 50mm f0.95 or the 50mm f1.2. Why did neither of these lenses make your list?
I hope you will post some more images here taken with and of this lens, and I'm glad you were able to find such a lovely example of a coveted lens; congratulations. Enjoy it.