Mouse in computer

One of my friends is a member of a pigeon racing club.  Their old clubhouse was going to be demolished.  He rescued the computer, took it home, then found that it wouldn't boot up.  He called for advice, so I reminded him that he could probably fix it.  I told him that computers often misbehave after being moved, and to check all wires and cables to make sure all the connectors were properly seated.  I told him to press on "everything" with reasonable force (not enough to hurt his thumbs).  An hour later, he called back with the question, "Is the computer supposed to have fluffy, fuzzy stuff in it?"  He said it looked like the stuffing from a car seat.  After a little more discussion, we guessed it was a mouse nest, since there had been an old couch in the building, along with grain bins for pigeon feed.  The mouse had probably entered through the back of the computer, through a missing rear panel cover plate.  I told him to take pictures before destroying the "mouse house" so I could show it to all my friends.  Here are the pictures:

(click picture for larger view)

After I cleaned the mother board, a visual inspection showed pins dissolved by  mouse urine, so the computer must have been powered up while the mouse was in it.