The two electrolytics and two diodes in the AC primary circuit seem kinda "strange" Yellow_Light_Colorz_PDT_09 . I'd ditch them, and use one of the Keystone (or similar) CL-90 inrush current limiters. (in place of the NTC, unless it is similar).
EL84s are happy with around 360VDC on the plates, 35 mA idle plate current.
THis circuit definitely needs some up-front gain, a minimum would be as in the "compact" amp design, better would be to emulate the VA / PI design from the ST-35, or even the 832 amp (using a 12AT7) that I posted recently.
Now for my bit of "plinker" engineering:
If 7247s or 12DW7s, 12AX7s and 12AU7s are too costly, just use a 6AV6 for the VA stage (equivalent to half a 12AX7) and a 6C4 for the phase splitter (equivalent to half a 12AU7). These tubes generally are low priced, even for NOS. For 12AT7, a 6AT6 serves as half of a 12AT7.
/ed B in NH