I think that GeoRichards is interested in removing the entire lock assembly from the door, not just removing the lock cylinder/tumbler from the lock assembly/housing. I think I am now confronted with the same problem on a 54/55 GMC. Others have posted this question in the past.
Here is a long and boring (and possibly confusing) web page with some photos: GeoRichards, is the first photo on that page similar to the back side of your lock assembly?
materman, I was writing my post when you were posting.
Your lock attachment sounds like mine.
