The stepper motors have a belt drive on both axises and it looks like 3:1 ratio so the 150 oz could really be 450? That's still not a lot but more than 150oz. I have a manual for the machine that states a rapid travel at 25 ipm. I'm not sure if thats good for a small machine of this size or if that number is slow.
Dickeybird your probably right about changing the motors, I will have to look and see if I can find some that fit as the X axis is really tight fitting.
Pjf134, I'm not sure how you can tell the age of the machine, but the guy who sold me his said it was from 1998.
Cycletec, I was thinking about the G540 again today and wonder what you would do with the two extra drives since your machine doesn't have the tool changer. It would be cheaper to go with separate drives and breakout board, but a little easier to wire if you use the G540. I also thought I guy could cut a hole in the back of the machine and mount the G540 in the back since there is some space between the two panels. A power supply could be located behind the door that covers the Z axis stepper motor. The retrofit would be pretty easy and all hidden inside the lathe.
Here are some pictures that show where you could mount the G540 and power supply.