• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Sprague TVL-4653 source?

Those haven't been made for 40 years. Replace it with a new 400V can for the 40/80/100uF,
plus a separate 100uF 50V part.

This one could give 40-40-100 @ 400V by paralleling two of the 40 sections.
.https://www.cedist.com/products/capacitor-ce-mfg-400-v-60404040-f