Well — was going to use a cable release off the left side for the
camera internals. The camera's shutter button has to be activated to raise
the mirror and allow winding the film to the next frame. But now it appears
we can finagle a lever on this attachment that will press the regular button
and skip the extra cable release. (Probably could have done the pinhole shutter
mechanism as a mirror image of the present too, if we'd thought about it.)