This is from the 1942-43 WLC parts book. It also lists 4706-41 Battery Ground Wire,which looks to be the same,but around half the length. I haven't found where that fits,yet,but I'm guessing it's an earth bonding wire for something.
Thanks Dave but it was the fasteners I was searching for. Your wire is correct but the parts books do not show the screw, washers, or nut for attaching the wire to the frame ground tab. I spoke to the author of how to restore your Harlet Davidsons and he related the parts books do not indicate the proper fasteners. He did however....have pics of original bikes showing a filister head with fine thread, peobably a 10-32 thread with nut.