hey fellow Strat cats. I've recently been looking at old blackface fender amps as I am starting to play live more than I normally do. Online I've found that many amps for sale say that the transformers, caps, speakers, tubes, etc have been replaced. I want as original and organic a sound I can get if I'm dropping a bunch of cash on one. I'm new when it comes to amps so I don't know what I should be looking out for. What can be replaced in an old amp and still retain it's sound and what shouldn't be replaced?