The short version is that I'm making two of WW2Chris' "things" work together. The grenade this is based on wasn't compatible with the boobytrap/tripwire fuses in this "thing": (https://www.thingiverse.com/thing:4281414).

This remixed part will work with either the normal grenade top or the boobytrap trigger model. (Best of both worlds!)

Much thanks to WW2Chris for every"thing". ;-)