Upload & Sell: On
You say you noted a "plastic" blade. Shutter blades are not plastic, they are metal, usually some alloy/titanium/etc. So that plastic bit of crap you found on the sensor was something else. Maybe it fell off the mirror, maybe it came off the focus screen shims or whatever, but it is not from the shutter.
Aren't some high end models equipped with carbon fibre or kevlar shutter blades? maybe getting mixed up on that.