Take a look at your King Seely drill press again and consider installing a 3-phase motor plus a VFD rigged for 120 volt input. Being an electronics guy, you should have a comfort level with this.
A VFD rig will be a lot less expensive than a new Asian-made drill press. You've got pulleys that can be put on a low speed to keep the torque up for low speeds since electronically varying the speed way down on a 1750 rpm motor will result in a loss of power.
The VFD route has some qualifiers. You can't use a GFCI circuit because a VFD will run some current down the ground wire. The circuit you use MUST be grounded. This detail kept me from using a VFD in the basement of my old house although that's been fixed now.
On three drill presses I had, I installed DC motors and controls. That was nice. The worst down side is the very slight DC motor hum.
A Powermatic 1150 A was about $3000.00 twenty years ago. They later started putting VFDs on their presses like they did on their wood lathes. Finding a good USA-made drill press in good condition isn't as easy as it once was. There are fewer for sale and ,as you've noticed, the competition is rather stiff. Condition is also a factor because a good press will be at least 20 years old, and more likely 40-50 years old. That's a lot of exposure to potential abuse and misuse.
Yes, I'm comfortable with the electric portion. Which VFD would you buy? I'm not clear why the three-phase motor. Does the VFD simulate three phases? (I don't have three-phase power at home.) My panel in the garage is grounded. It was installed just for woodworking equipment. Better yet, where would I get a DC motor for the King Seely (Sears)? I'm an electronics guy, not a motor guy by any stretch of the imagination.
On a second note, where would I used a drill press on its highest speed? Not for metal, not for Forstner bits, so?