Rich, If it's the GE servo's I am thinking of they are quite large for their HP size compared to more modern servo's, check with the retro-fitters in your area, a lot get junked when stripped off of older machines, there is North American Industrial in Mississauga 905-565-6166, you may want to check with, they do some retrofitting. They also have a technician that worked on the original GE1050's etc.
As a last resort take the info off the motor label and look for sub's. If they are larger motors, look for Getty's or Fanuc DC servo motors on ebay, They are pretty rugged and flexible as to adapting to other drives. BTW what control do you have?.
Al
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.