Dear Steve,
marvellous. The circuit diagrams are almost identical. I lowered the amplification by means of the 470 ohm resistor from kathode to cathode. This brings the bridge a little bit out of balance for equilibrium, but is was only 3 volts at the grids and that can easily be corrected by the pos control. Otherwise I could have used two resistors of 220 ohm.
As you can see I designed at a somewhat higher anode current, so the anode resistors can be lower (22k) than the 47k you use. I hope this makes the HF cut-off frequency higher, but that depends also of the mutual capacity of the deflection plates of course. The EF80 can have that higher current. In fact 10 mA, which can occur when the deflection is statically at one end for some time. Even then the max. dissipation of the tube is not exeeded.
Presently I am thinking about the EHT generation........ Then I can fire up the CRT and see how sensitive it is for magnetic stray fields.