Thanks Jon,
I originally posted the symptoms and observation in this post. And then after reading this one about a more modern pulmor motor (vertical, not horizontal), I realized my sounds were were very similar.
I decided to take a second look at my motors, and when I put it in the cradle inverted, the front motor made the noise 100% of the time after about 10v. There is a lot of play along the axis (side to side since it is horizontal), and laterally (nearly contacts the field, but not quite).
Further, when holding the motor vertically out of the engine, the armature for the rear motor spins freely for a second or two when spun by hand. I can even achieve this by using my thumb to spin the idler gear and the armature spins smoothly for a second or more. The front has a "wobble" that dampens and kills all rotation almost instantly after i finishing spinning.
Based on that, I assumed one of the bearings might be worn.
I can see my thinking on removal was backwards. I was worry about removing the gear from the splines, it never occurred to me to drive the shaft through. Based on that its easy enough for me to build a saddle and use press it out.
And yes - Jeff is the best for parts. I bought my bearings and other parts from him. I will always check him first.
**** - even if I am wrong, I love doing new things and learning. Should be fun.