Those are nice and beefy. Somebody who isn't worried about size and weight might like a holder in a handle like that. I made a prototype holder a couple weeks ago that uses set screws like the Pika did. Mine uses two set screws which I think will be less likely to loosen than the single one in the Pika. I also used self locking Nyloc set screws which I don't think will loosen due to pounding. The nylon is visco-elastic and I think the very high viscosity will keep them from moving due to impact. Needs testing. Your handles would be perfect. Drill two holes for access to the set screws and glue the handle on. Did you glue them on or did they stay in place all by themselves?
The market for hand drills is incredibly small but if anybody wants one like this, they are much easier to make than my bayonet type.
Russ, send me a message if you are interested in my prototype. I could send it to you if you wanted to test it out.
I'm always interested in trading for stuff.
Two set screw drill holder with hardened striking surface.