After checking out the Motor Driver board of the non TMCC switch, I have concluded that the board is NOT suitable for directly converting Non TMCC switches to TMCC switches by just adding a connecting cable between the new Radio PCB and the old Motor Driver PCB. The reason is that the Radio PCB gets its power from the new modified Motor Driver board and requires +5V and the old Motor Driver PCB of the NON TMCC switch (part number 691-TRC3-F ) outputs track 3rd rail voltage and NOT the +5 volts that the TMCC Radio board requires. Using it without an external +5V regulator would damage the Radio board of the TMCC Switch.
I have successfully converted my Non TMCC switch to Command Control by installing a Radio board, new Motor Driver board, push button switch, and making up a connecting cable from the Radio board to the Motor driver board. It functions perfectly. Now wither or not this is COST effective to make the conversion is yet to be determined, but it was a fun project and proven doable. 
