The wiring on that looks a little funky. It has been modified where it goes into that block. Isolate and identify the path of the two wires and hook up a positive and negative bypassing the block. That black block is a insulator and not conductive. That ground wire connected to it is not going to work.
Try connecting a positive to that wire that goes up to the motor and ground to the frame somewhere. That green wire is not connected to anything.
You also have an issue with that commutator. It is very worn. Take a cirucuit testor and test the commutator like this. Set to resistance and touch two commutator plates. See what the reading is. Move one plate to the left or right, see the reading. Continue in that direction one plate at a time until you have gone all the way around. The readings should be the same or very close. If any two plates have a wide varying reading than the other, you have an open circuit and a bad armature. To make this make more sense, if you number the plates 1 through 4. Test 1 and 2, then 2 and 3, then 3 and 4 then 4 and 1.