I used a Pacific Scientific DC motor that had a shaft (5/8") the same size as the OEM Emerson motor . This allows the use of the original pulleys and belts.

I made the motor adapter plate from a piece of 3/8" aluminum and a piece of 3/4" aluminum. I used a round-over bit to mill the recess for the motor.

I made the controller bracket from 1"x1"x1/8" HR steel angle. It bolts to the same holes as the original switch bracket.

I bought the Dan Foss C150 controller on ebay. It is currently using a pot to control the speed but it supports a 0-10v DC signal to control the speed. This can be obtained with the use of a board like the Digispeed boards from Homann in Australia.

I used the original pulley on the motor and the original belts too.