Well, I got the horse before the cart again wandering through Eb...y I just won a Schneider Xenar 240mm f/4.5 from around 1960. Looks to be in great shape, but no shutter. I have seen the 300mm version of this lens in an Ilex #5, but don't know the shutter size for this baby. Schneider's vintage optics page lists this: Shutter Size IV/10+5FS Is the IV referring to a #4??? It is not referenced on S. K. Grimes list. If anyone knows so I can start the hunt for a suitable shutter, I would appreciate the help.