At the risk of blasphemy: consider making the vib oscillator and driver (follower) with transistors or an IC or 2 and eliminate the need for the extra tube hole.
I've said this before. If you use a 12DW7 to drive and recover the reverb it will free up half of a 12AX7 so you can convert it to a long-tail pair phase inverter. That will make a big difference.
You guys are clearly several levels above me here...wouldn't even know where to start or know if I was doing it right!