Internal pictures of the HP E8285A service monitor.
These pictures of my "parts unit" It's a cellular-only Agilent model.
My "real" unit is HP branded, a little older and covers HF-Cellular bands.
The parts unit was fairly dirty. I took it apart just to see how they are made and ended up having to clean it a bit. I pulled almost every module and put it back together and it even worked still. :)