Maybe its the "Allen Bradley" carbon composition resistors carrying the magic!
Maybe the ESR of the caps use even with the same value and voltage rating are different? Maybe the Selenium rectifiers impart a magic sound? Solder maybe?
Ahh too many things to consider. IMO, any restored vintage amp will measure better but does not necessarily mean will sound better. True restoration experts take into consideration important parameters like Operating Points, and don't just buy and replace a component from new production materials because they are close enough. They have to consider and preserve the unique tone of the amplifier for example. This why NOS parts sales are increasing. Found any audio components with Western Electric on it and chances are, it will sell.
So, if I'm in your shoes, I will be patient and look for the same amp that had been restored properly. Or better yet, learn to do the restoration yourself, step by step, so you know which one change the character of the amp as you change components inside.
But I will put my money on AB resistors!
he,he,he,
regards,