Thanks Joe, you have been a great help thanks for posting these photos
All...
These are some photos that I took with my phone...
There are 3 small blemishes on the back plate near 3 screw holes. The finish is smooth, no bubbling so it looks like tarnish or oxidation not sure. The compartment is tightly packed so you will see that there are some finger smudges on the inside upper area of the controls back plate caused when I was getting the plate in place to take a photo. Dislike opening the back.
As you csn see in the photos ....The inside of battery plate, battery compartment, control back plate and control compartment are all clean.