Well.....no luck. Made the green wire ground connection and with high hopes fired everything back up. Radio signal remains unchanged.
I also measured the resistance between the Foreplay and the Dynaco. This was exactly the same as between Seduction and Foreplay as well as terminals 13 and 14 on the Foreplay. Meter beeps with 0.00 reading and then climbs to 0.5 and settles on that number.
Lastly, I hooked the Dynaco up to another outlet on a different circuit using a heavy duty extension cord thinking this may determine if the dedicated outlet had a grounding problem as some had thought possible. Fired it all back up and everything remained unchanged, including the voltimeter readings.
I'm obviously disappointed the fix was not obtained, but still determined to do what I can if there are any next steps you all can suggest? Appreciate the continued support and guidance with this problem.