Quote Originally Posted by MattKing
You may also be able to use the pentaprism that Mamiya made - it works on my C330 and C220, but I am unsure if it fits the earlier cameras.
I have both a porrofinder and a pentaprizm for for my C220. It also fits my old C2. The porrofinder is both a smaller image and not as bright, but weighs less.

Dave