Graphic Kowas are a real mixed bag. Some can be completely unscrewed from the barrel mounts, these (in 150mm) are direct fits to a Copal 1 (not 0) shutter. I have one. Others can't be removed at all, and I've seen some where the front cell could be unscrewed but not the rear cell, or maybe it was the other way around.
Assuming they can be unscrewed from their barrel mounts, the longer focal length (210mm, 240mm, 270mm, 305mm, 360mm) Graphic Kowa, Kowa Graphic, and Computar fit a Copal 3S shutter, which is a little smaller than the much more common Copal 3. And to confuse things even further, some Copal 3S shutters are simply marked "3".
Last edited by Steve Goldstein; 06-16-2013 at 08:01 PM. Click to view previous post history.