...It looks as if the datasheets I have run it in class C for telephony. I'm presuming that hurts linearity and I'd want to try to run it in class AB? ..
Class C was for plate-modulated AM phone, where the tube
was only amplifying the carrier, not the modulated signal.
For SSB you certainly need AB1 or AB2 instead, and the
original data sheets probably list that only for audio (and
possibly for two tubes in push-pull). If you are thinking
you might run SSB, then I'd recommend designing it
for AB1, then add an option to run it AB2 or C for CW
if you want to.
Note that the plate load impedance may change if you
are trying to get more output power for CW.
IIRC the 807 doesn't work well in grounded grid (unless
you modify the grid connection) but should work well as
a grid-driven stage, possibly with resistive loading on the
grid for stability. My old Handbook may have had a couple
circuits using the 807, before they got replaced by the
newer 6146. But any of the 6146 or similar stages should
give you a good idea of the circuitry, even if the bias
levels are a bit different and the output less with the 807.
The HW-12 / 22 / 32 SSB monobanders had an output tuning
capacitor with a fixed load capacitor, assuming the load was
close enough to 50 ohms. That saves a big variable cap. The
tuning cap in my HW-12 was fairly small, as I remember it,
so I assume that there was a lot of fixed capacitance in parallel,
and the tuning range limited accordingly.