Re: Question for dem folks who know about dem maplifiers
Yarr, should be good with vibrochamp type caps.
If you want, you could measure the B+ voltage(with care, it is prolly 300+ VDC) and simply buy caps rated for more volts than what you measure.
But i suspect that vibrochamp ones would be a proper volt spec. As a guess, you probably need at least 450v, possibly 500v, caps. If it is an exact copy of the vibrochamp, then the PT voltage can maybe run a bit higher than what in the modern era we might expect for a single ended 6V6 amp.