Stripped teeth on window crank mechanism where meets handle?

[sixty4c10]

How would you guys go about fixing this situation? The teeth on the window crank handles are chewed up from PO using vise grips as handles (ugh!). So I bought new handles, but obviously I need to do something to get them to grip onto the mechanism... Any ideas? I was thinking about drilling a hole straight through the handle and that part of the mechanism to fit a cotter pin or bolt, but doubt that would come out straight...