Hex is Skill RotoHammer from the 60s. Good quality carbide and steel.
The RotoHammer was a HEAVY brute, and was one of the first electric hammers worth having. It was nicer if you had a 2 wheel cart to move the damn thing and steel suitcase it came in, and a 10 foot pipe to screw into the auxiliary handle. If that drill caught a rebar, you could count on pain before it shut down, even if you were smart enough to have a foot switch.
RotoHammer came in 2 or 3 sizes and would chuck up to a 2" twist bit or 3" Tilden bit. I have a 2" tilden that has and will drill through 4 feet of concrete all day long for one of the big RotoHammers.
Skil also made a similar looking hammer called DemoHammer that was built to drive chisels with no rotation.
The Dayton bit is a W W Grainger tool, possibly from the 70s.
In that timeframe all manufacturers had a mentality that you would buy bits only from them for their tool and charged till you bled. None would license any bit manufacturer to sell bits that fit their tool, and they all employed Lawyers to make sure.
A couple bit manufacturers, Grainger being one, discovered the glitch and started selling adapters that went from manufacturer drive to A taper, and put a hurt on manufacturers.
Patents ran out around 1980 and bit manufacturers offered bits for Skil, Bosch, Hilti and others.