I have a Maestri 3G electric stapler, and have ordered (and received) a replacement plunger. While taking the thing apart, a spring came out, as did a small silver washer (or maybe it fell out of the work closet beside where I was working). Also there is a metal disc type part where the shoulder of the plunger hits, that has broken into pieces. I am looking for a parts/assembly diagram. Or, failing that, a video on how to take this gun apart. Id like to 1. Order the part that has broken, and 2. Put this back together so that it will function properly