I remember when I worked for Transitron, when a module failed and was returned, it would be popped into a "stripper" -- a nasty chemical which would take off the epoxy including that making the glass-epoxy printed circuit board, leaving just the glass fibers (loose), the circuit traces (even more loose) and the resistors (only the carbon element and leads -- the Bakelite around them was also stripped off (along with the color codes). You really had to know what it looked like before potting to identify what you had. This was before transistors started being made with epoxy cases, and *long* before ICs, but those would have lost their case as well (along with any indentification markings).
Later (when working for an Army R&D lab), we had something which looked like a benchtop oven, but weighed a ton. It was a small X-ray machine, and you would put a sheet of Polaroid film under the device being studied. If you wanted a 3D view. you would prop it at an angle and shoot another film, then set them in a viewer.
You still didn't have access to the part numbers on chips, but you could at least get a good clue as to what was connected to what before you threw it in the stripper. You could probably measure the values of the resistors. Not sure whether the capacitors would be capable of being measured at that point, however. :-)
And trying to get the epoxy off by mechanical means is also a problem since it will almost certainly lose the markings on the chips -- unless you are dealing with something old enough to have metal cans on the transistors and the chips, or ceramic packages for the chips.
I would suggest that you start with some 4x5 Polaroid film and your friendly neighborhood dentist. (You will need the processor for the 4x5 Polaroid film, of course. I've got one to go with my 4x5 Crown Graphic, but I suspect that most people -- even those with a photographic interest -- won't have them.
Good Luck, DoN.