Thanks, Jim. I've been watching auctions lately, but the prices are a little crazy these days. A friend of mine who has a camera shop has a Packard whose outside measurement is just over 6", which I could have for a song, but unfortunately it won't fit any of my cameras. (Is there any way to adapt/trim a Packard to fit a smaller board? The absolute maximum my camera could handle is 5 1/2".)
One possibility with the bigger shutter is to mount it on a board and get one of those lens chucks aperture thingys to mount on the other side. Then the chuck holds the shutter to the front of your barrel lens. So the shutter's up front, not behind it.
He is no fool who gives what he cannot keep..to gain that which he cannot lose. Jim Elliot, 1949