What am I missing here? if there's only two hooks and one is the full cock
ain't the other one the half cock?
There are two hammer hooks that create the full cock shelf. They're arranged on either side of the hammer with a gap between them.
One of the hammer hooks was longer than the other. I made them equal length so that the sear would escape both at the same time.
None of this has anything to do with the half-cock notch.
Recent Springfield hammers have the normal hammer hooks and half-cock, with an additional quarter-cock shelf similar to the Series 80 Colt hammers. Their reasoning for that is a mystery.