I hope I'm not being a pain by asking so many questions.  I was taking apart an elgin pocket watch and when I removed the center wheel it fell into 4 pieces.  I have the shaft, the wheel, the pinion and what looks like a tiny washer.  I wasn't really looking that closely when it came apart so I can't be sure about the washer.  It looks like the shaft is keyed to the wheel and that the pinion threads onto the part of the shaft that sticks through the wheel.  But where does the washer go?  Also, h