Problem 38 Water Tower

[Railfan1588]

I'm sure as most of you know, the original postwar 38 water tower was notorious for leaking. Any way, I recently picked up an original 38 tower that is in excellent condition, and even had the original funnel. The motor works fine on it, but not suprisingly, I am having trouble with water leaking. To best explain what is happening, the water is coming from the pump housing, and seeping up through the hole that contains the amature shaft. It then comes out right under the amature, and spills out onto the sides. Whenever I wiggle the amature, the amature shaft is moving ever so slightly back and forth, which probably is allowing the water to seep through. Anyway, what I am wanting to know, is there any kind of replacement gasket I can buy that i can put on the amature shaft so the water won't leak through anymore?
Thanks
Nick