I recently purchased an ancient Nikkor Q Rangefinder 25cm (250mm) f4, with a Bronica mount. If my research is correct this lens is around 50+ years old.
I took it out for the first time last weekend with a roll of Ektar 100 and I'm happy with the results.
While this lens has really pleased me, I have a line on a 18cm (180mm) of the same vintage, possibly better, a Nikkor H at f2.5 and I am tempted.
So, how much is to be gained with the 180 as opposed to the 250?
They are both Rangefinder lenses with adapters, my 250 has the Bronica mount the 180 has the Nikon F mount, they would be interchangeable, affectively giving me 4 lenses, for the two formats.