It looks DC because it looks like it has commutators on the end of the armature.
You can start out at a low DC voltage and see which way the motor starts turning, and make sure its turning the right way. take that cool little spring belt off to take any load off the motor.
The more voltage you apply, the more torque (and speed). so, with no load and a low voltage, make sure you have the proper polarity (that the motor is turning the right way) and then put the spring/belt back on, and increase the voltage until it is able to turn the mechanism.
add a volt or two, and that is likely the voltage you are looking for. Unlike a AC motor that uses the 60 hz from the wall as a regulated time source, it looks like your clock still uses a pendulum as the regulation.
so, the speed of the motor is not important, as long as it turns.
You can likely do this with batteries. I would guess it will start working on about 7 or 8 volts. (but use larger batteries.. you might want to start with a 6v lantern battery to supply enough current)
Also, please show some more pictures from other angles.. I'm still trying to figure out what those resistor looking items are for.