I like this thread. Here are some additional details regarding using the CMS on 80M CW.
The transmitter module was removed from the case and used standalone. I left it 100% stock. Receiving was ably handled by a restored BC-348-N. The manual states that one could use 6L6's at 450V from a line operated supply or 6V6's at 250V from a battery or hand crank gen. I used a bench PS. First up was the 6L6 and it had keying problems with a crystal. I switched to a pair of JAN metal 6V6's and it keyed beautifully with a rock or as a VFO. There was a lot of pulling with the VFO and a thermal warmup period so I elected to go with an FT-243 rock. Using the lowest Z output coil tap I was able to get 5W output with a little over 300V applied (max rating for a metal 6V6).
I will admit that I did make one teensy weensy temporary mod. I snuck a thin pair of wires through a factory adjustment hole in the rear. The wires were tack soldered to the B+ ON/OFF slide switch on the front panel. This allowed me to use a foot-switch operated T/R relay for snappy QSO exchanges.
With my antenna tuned to 50 ohm and measuring 5W, I then swapped the antenna for the 50 ohm input of my spectrum analyzer. This is how I recorded 1.6mW of backwave. The 200 mi path between my friend and I is a good one around dawn. When he copies me 599, the backwave is heard. It's not a one time event; it happens month after month. There is a ceramic neutralization trimmer in the CMS circuit that I left untouched. Was it adjusted for 6V6 or 6L6? I don't know. I did not readjust it for fear of breaking that cap.
Note that the telegraph key switches the B+ line. That is why I chose the Navy flameproof. Lots of fun using this little rig. I welcome comments on the usage of the CMS set.
Dennis AE6C