After drilling out the antler and test fitting things, I trimmed up the brass a little and set it all in place with 2- ton epoxy.
I coated the end of the antler with bees wax to keep the epoxy from sticking to the sides of the antler and let it sit all night. This morning I cleaned it all up and polished out the brass.
It feels good in the hand and should make a good skinner.
Rover, I'd say you're right about the steel. A new file will barely scratch it, but it's not so hard as to be brittle. The blade is .125" thick, so it's pretty stiff. After polishing the blade a little, just a few strokes down a ceramic and it will make hairs jump off at the slightest touch.
I'm not sure what I'll do with the back of the handle. I can't decide to cap it off with more antler, bone, wood, brass or just leave it bare.