I just came into possession of one of these missing the ground glass focusing back. Finding an actual SG back seems like it could be difficult and $$$. The ground glass from a crown graphic will mount if you remove the slider clips from the rotating back. But that means you cannot use roll film backs Etc. The Crown graphic has all it's parts but the bellows is shot. Someone has suggested that a ground glass back from a Calumet cadet/Cambo will work. I am looking for a way to make this a working camera and was wondering if anyone had working knowledge of other backs that will work/attach without removing the sliders?