A word of caution about using a windscreen motor.
I used one in a recent project to power a small winch. It worked fine at first, but after about 30-40 times it lost power.
At first I assumed the (12v) battery needed recharging, but it was OK. After stripping it I found the problem: the brushes were tangential to the commutator instead of being radial, which meant that a larger area of brush could contact the commutator - making for a smaller motor for the same power. And this is fine for a motor that runs in one direction only.
In my application (a winch) it was always run in both directions every time it was used, and this eventually wore another arc on the ends of the brushes as they moved slightly in their guides. After a while, each brush had two arcs and only half its original contact area, thus reducing the power of the motor.
If you don't need full power, then it would probably be OK, but be wary if you need full power.
By the way, the older types of windscreen motor used radial brushes, but I wasn't able to find one - and I needed the maximum power. I had to use a different source.