I’ve tried things like that (couldn’t get rid of my Metro fast enough btw) and IME no way. Even the very best tubes I have only can take an amp so far. I could use all my various vintage Mullards, GEC’s, Bugle Boys, RFT’s, etc into amps like those, have generic JJ’s in my vintage Marshall (which it actually currently has lol), AB the amps through the same cabs of mine with pre-rola 20w GB’s and I’m sorry those amps get slaughtered by the Marshall to my ears and imo tonally outclassed in every way, especially with being raw, organic, warm, tonally mature vs the more filtered out bland sound of those amps (comparatively sterile and less reactive/lively to nuances in playing). It’s classic example of comparing fresh squeezed to from concentrate oj. Same flavor, different levels of quality