When I first started I used a hand impact---the kind that uses a hammer, the original screws were a large straight slot, it wasn't till much later that the square recess head type was used.
Now I have a better setup, a curved base, an expander to fit in place of the armature, and a driver that fits in the press and uses a wrench.
When painting electrical parts you always have to be aware of the electrical path, too much paint can prevent proper operation by insulating the ground path.
---the brush grounds to the end plate, the end plate grounds to the field housing, the field housing grounds to the bracket, the bracket grounds to the block ---paint all the parts too good and you have a bad ground. ---most generators, and starters were originally assembled bare, then painted, in our attempts at restoring things "better" we cause problems that the factory never had.