So I have spent days tracing wires and comparing the original and later production drawings to my radio as I disassemble it. I have figured out most of it but can't seem to get a handle one one section. My radio for the most part is the later production 610 without the phono section. Where the difference lies is my radio does not have the resistors #17 and 18#. I also has an extra 20 ohm resistor between pin #6 of tube 6a7 and ground not shown on the drawing. I find it odd that this same value of resistor shows up on the original model 610 as item #9 but is not tied to 6a7 and there is no #9 item on the later version drawing. Also resistors #16,17,18, as well as cap.#15 on the original drawing also are not in my radio. Any ideas or comments? anyone know of any other drawings out there that might show this version? Should I just put it back the way it is/was? Thx.