Been so busy. Sorry...
First switch just sends the signal to either input of the preamps. In one position to the 2204 tube, in the other, to the SL tube.
The second switch switches between the outputs of the 2204 tube or SL tube to the input of the cathode follower.
That's it in a nutshell. If you look at the picture of the basket case rebuild above, you should be able to figure it out. I put the volume for the SL Normal gain in the back panel as I ran out of room in the front panel... The front panel has the gain for the 2204 and the gain for the bright of the SL. I kept the pre-phase inverter Master volume for both settings to keep it simple.
The SL inputs are permanently jumped.