Thanks all for the help and suggestions.
David that truck diagram on page B-90-3 looks pretty well right on, and the upper swivel plate appears to have a large tab behind the motor that affixes to the main truck frame by way of a longish screw that goes thru from the top and attaches the rear power pickup underneath the truck. So I will try removing that screw and see what happens.
"When in doubt; use a bigger hammer!"
Rod