The electrolytics are used for smoothing power rail voltages. Unless you have evidence that the original ones are faulty, you won't notice any sonic difference if you replace them with new ones of the same value and voltage rating. The rating on the ones you have is not high enough to risk using them.

The blue capacitor is a Mallory. Those others are premium and their use in a lot of other equipment upgrades so you're good on the electrolytic's. You don't want to change out the ceramic capacitor. Basically don't screw with the electronics. Likely the most decent probable upgrade would be a change in the output transformer. Every Transformers sounds different by every manufacturer. It's sort of like 11 secret herbs and spices or the recipe to Coca-Cola. And that's where a lot of these types of microphones fall on their faces due to a substandard Chinese output transformer. Some even offer at the factory upgrades to better output Transformers. Not sure about that one? And of course there is always some one out there that likes to hot rod all sorts of stuff, which doesn't make it better, it only makes it different when it comes to the subjective world of audio recording. Better is only better if you think it sounds better to you and not to the salesman who's trying to sell you it or the magazine advertisements.

It's always fun to upgrade something when you have nothing better to do. Most upgrades just seem to make crispy sounding things all the more crispier? Where these items lack is in having great warmth and depth. Which is usually fine when you're talking about rock 'n roll of the homegrown variety. I've used them if I had to order, was told to when there was nothing else to use. It's never going to be anything to write home about however. I mean I don't purchase a pair of pliers and then put it on the grinder to make it a screwdriver. Or even add the screwdriver modification without taking out the function of the pliers themselves. You already know what those 81's sound like, they're killer! And sometimes for others, there is no hope... oh the humanity. But it serves the purpose until you're ready to move on and that it's still useful once in a while. We collect these things for a living I mean a hobby I mean a living I mean to be looking for work.

Leave well enough alone.
Mx. Remy Ann David

As Remy says, the output transformer is probably the single component that would produce the most benefit from an upgrade. However, sourcing a significantly better transformer to the same electrical specificatiions that would fit in the space could be difficult.

Can you tell us what the 5 integrated circuits are? There may be one or more of those that would produce an audible improvement through upgrading. That's assuming you have nothing better to do, of course...