damn, thats a lot of work.
an activity light may be the easiest way to go. use a transistor to trigger off one of the legs that does the patching.
or, how about this. an RC circuit tied to the reset line to trigger something powering the LED. we know that to turn the chip off we hold onto reset for 5secs. then all we have to do is find the correct resistor and cap values for 5 secs and a transistor of some sort thatll power the LED properly. this is probably not a fool proof way of doing it, but it may be something to start with.