Take a late 50's Fender amp. Say it's been serviced ten times since 1980, and has seen a lot of use. The original tubes are long gone. Caps have been replaced, and a few other things. Wiring and so forth. Assuming the original speakers are in good condition and no serious mishaps or abuse had occurred, does this amp truly sound like it did when it was new ? Can it be expected to ? What I'm getting at, is a vintage amp serviced with other than the exact original parts and tubes after these parts ran out of stock and ceased being produced, really the same amp tone wise ? If the consensus seems to lead toward "no", then it will help me decide whether to put money into an old Sano amp I bought off cl. I know todays tube makers are betting better, but what about caps and other parts ? How do these new parts affect the tone of these old amps ?