WTF are you talking about??? Ok so change them because they're old. Ya ok. Whatever. Biggest bunch of fn bullshit from techs is "gotta change the filter caps". Bullshit. If it ain't broke. Get it? I've had more Marshalls than years you've been on this planet. Never had one vintage cap fail, ever. And the one time I did notice them leaking, I changed them. No problem.
If your so goddamn right on your bullshit about the caps, then why are my 1972 Daly caps running strong and have no signs of failure? The amp would flatten anything you have including your precious blanket over speakers Bogner. Why are the original caps running strong in my 1964 Fender? Because they're still good. That's how it works.
60 fn year old filter caps still running strong. No worries.
I don't give a rats ass on what degree you have or how adept you are a building an amp. "Gotta always change filter caps" is a fucking bullshit statement, period. Maybe on a newer POS 5150 or the like with shit caps, IE not LCR/Daly then maybe so...but on these vintage amps they can and will last 50, 60+ years.
Now you can go fuck off and play with your solder gun for a while.