I have a C2 that I bought here on RFF. It came with the chrome 105mm f/3.5 lens, mirror finder as well as standard WLF, and handgrip. Everything came in the original boxes. The camera was in unbelievably near mint condition mechanically. The only thing wrong was that the old vinyl covering had cracked. The price for this gem with all the accessories was $110. I had Frank Marshman overhaul it, and put brand new leatherette on the sides. Now it really is gorgeous. Even with Frank's overhaul, the kit was $230.
I also have a C220F, from RFF. That one is nice also.
In spite of the more "primitive" appearance of the C2, I love it. It just has such an earnest look to it.
To the point: any of the later finders fit and work perfectly on the C2. This includes the magnifying chimney finder, the metered finders, and the prisms.