Jukebox Repair: Needs some help with motors.

I'm in the process of restoring a 1950's jukebox and I'm looking for recommendations on what kind of modern motors to use.

The juke has 2 motors, and 5 switches, as well as 2 solenoids. The switches and solenoids work fine. I plan on hooking these up to an arudino, so that I can get the read switch on/off positions and power the motors.

The 2 original motors have partially seized up. Over time, the casing of the motors has deteriorated and the large magnets in the motor are grinding up against the shaft so they can't spin. (Forgive my terminology, I don't know what this stuff is called). If I remove the magnets, the shafts spin freely and cause the worm drives to spin the mechanisms of the jukebox.

My plan was to replace the motors with some leftover Nema 17's I have from a CNC that I upgraded to Nema 23s. I made some couplers to go from the 5mm shaft on the Nema's to the 1/4in shafts on the worm gear shaft, and they seem to work ok. The Nema's I have are SY42STH47-1684 which have a rated voltage of 2.8v.

I hooked up the adafruit motor driver shield, and the motors worked for a few seconds, turning the mechanisms in the juke. However, apparently the Nema's I have aren't really compatible with the shield. They spun pretty herky-jerky, and the external power supply I was using causing the bottom of the Arduino to get too hot.

I also have a gShield that could run the motors, but only as far as I can tell, it's really only useful if I want it to be a CNC.

What kind of motors would work for this application? Is there anything that will work with the adafruit shield? I'm trying to keep costs down on this project.

I don't need to know how many degrees the motor has rotated, as the motor will only really rotate until a switch is triggered, then shut off. One of the motors needs to be bi-directional, while the other is uni-directional. There's a bit of torque needed to turn the worm gear shaft, but not a ton. The Nema's I have weren't losing any steps for the few seconds they were working.