I have a Leica 391427 K Kugellager IIIc camera my father bought in early 50's from an officer that returned from Germany. The top of the camera is grayish black and has a base plate that appears to be stainless. I have been told that the base plate should match the top. I wouldn't think that the camera which was fairly new back then would have had it replaced. I would like your thoughts. Thanks in advance.