PeteM said everything I would have said. Pay attention to the motor number - the rare earth magnets are a significant improvement for two bucks more - and Pittman still sells the Alnico motors!
Weaver cheaped out in two places - first, with motors, and then with non-aged plastic. Using an Alnico motor with solid bearings in an application where radial force is applied is a no-no. Charlie pIttman Jr. told me that personally.
Aging the plastic before machining is why NWSL and CLW gears rarely split.
