Will do. Thank you for the heads up.
I'm going to have to sand it a bit because there's a tiny roll of metal at one side of the key grove on the crank. Looks like the key pushed the metal a tiny bit as it started to shear.
Regarding that key, I see two options on the schematic, both are number 24 on the crank assembly schematic.
https://shop.briggsandstratton.com/pages/parts-lookup#/Briggs_%26_Stratton/331777-1107-B1/Camshaft%2c_Crankshaft%2c_Cylinder%2c_Engine_Sump%2c_GASKET_SET_-_ENGINE%2c_Lubrication%2c_Piston%2c_Rings%2c_and_Connecting_Rod%2c_Warning_Label/3317771107B1/40220002B/y
One is for date code after 12071600
The other for code before 12071700
Aside from being thoroughly confused by that seemingly contradictory information, my date code looks like 080320ZD.