I think I will remove the crossover from the cabinet. I don't want the wires coming out the port, though. I could add a second set of binding posts and wire the tweeter to one set, the woofer to the other and then connect the crossover to the respective posts, yes?

I'm guessing that the 8 ohms should be about 3 dB attenuation on the woofer? And I'm wondering why it wouldn't be better to decrease the attenuation on the tweeter? Maybe (certainly) I don't understand the Zobel thing.

It is for certain that there is synergy between the 2A3 tube and the Pi's. So much so that I don't believe it is possible to describe the sound in terms of one component or the other, even though I ran the Pi's for so long with different amplification.

And now with some hours on the tubes I'm getting that blue glow!