Hey!
Considering those old caps are 20 years old. New and better caps will "improve" the sound, but that doesn't mean you'll like the end result. Also, good caps of those values that you need 4.7uf, 10uf and 33uf can be costly and bigger than what's in there right now.
Another question to ask is... it is worth doing it? Putting in more expensive parts doesn't always guarantee you will like the end result. And you won't know until you put them in, break them in and listen.
Anyway, it can be a fun thing to do and experiment if you have time and money. Good luck and keep us posted on the result.
Buddy