As promised, here is the current schematic for my tube preamp:
I wrote an (almost) legible version. I'm still making some component changes, so this one isn't completely accurate... but very close. This drawing is for a single channel of course, for stereo operation you must duplicate the design. (Power supply can be shared among both channels).
I also resolved the issue with the lower half of the signal being 'squashed' before the top... I still have a lot to read about tube biasing ;) .
The current output of this design (as seen above) has a fairly constant output across it's frequency spectrum from 20Khz to 20 Hz, so I am pretty happy about that. A 1.5v input gives a consistent 1.5v output. I'm very close to finalizing my first design...