I still have my bronze 16x11" 3-blade prop lying around here, coming from my M376.
It fits a 1 1/4"shaft (31,5mm) with 1:12 conus and 8mm key.
I have recently put it up for sale in an ad , were you could see some pics (click the link).
It was running fine, I replaced the shaft going metric, so the prop no longer fits. Now using a 18x12" Maxprop.
I am looking for an offer of around 100€+postage.
As a spare, I can also propose my old 2-blade prop, same specs.
Let me know when interested.