Given that the capacitors providing negative feedback to the op-amps have been cut, as have the capacitors in the anti-aliasing filter, you get the impression that someone didn't really know what they're doing. The wires running to that switch suggest some attempt to make the anti-aliasing (low pass) audio filter switchable. But given that some of the components the filter needs to work have obviously been cut, I doubt if it would work as expected.
The wires running to the memory expansion are probably address lines as required by the additional memory.
The hot glue on the PLCC socket is some bad attempt to fix the socket after someone has tried removing the IC using a crowbar.
And the hot glue covering everything else is anyone's guess.....
What a mess with all that hot glue...
Perhaps the resistors for the audio are inside the shrinkwrap? Maybe it works...
