"New" RCA TRK-12

[old_coot88]

That's a neat idea for equipment in which there's no ohmic load on the B+ supply with all the tubes removed.
But in TVs of this vintage, there's often bleeder/divider resistors of less than 20K across the B+.
With the forming voltage supplied through a 100K resistor, the caps would never see but a fraction of their rated voltage.