I popped the back off last night and took some more pictures. I like how the back is held on with clips rather than screws. Very easy to get on and off.
So far I see a mix of bumblebee and maroon caps.
I assume the bumblebee are paper inside and should be replaced but what about the maroon type ? Are these plastic film and generally OK or should I shotgun them ?
Also any thoughts about the missing x-ray shielding ? Would some galvanized or aluminum sheet metal be sufficient ?