[Mike L]

I haven't started on mine yet. it is next in project order after Thanksgiving as I really needed it during my last radio project. I watched that video as well. Very informative. I don't have the resources he has but I understand the process he was using. Mine is S/N D58432. I found a  schematic for mine dated 1957 which I believe is when mine was made by some of the markings inside. I can email you a copy if you haven't located one. Its actually the operating instructions as well. It looks to me that the positive ends of 108b & c are connected in relation to the negative side of 108a. Others with far more experience than I would be willing to help I'm sure. This is a great forum with a plethora of info and great people.