Another thing I would mention here is that I am making a big assumption that those green Nichicon Muse bipolar are being used for DC blocking signal caps (why else would you use a bipolar?). If he is actually using these for power supply filters, then Elna Silmic is not the best choice. The best I found is the normal Nichicon Muse (UKZ) series. If you do this, better make damn sure you put them in the correct polarity (put in an electrolytic reverse polarity will probably blow the cap pretty quickly). Might have to use a multimeter to determine which pins are positive/negative.
Also, I don’t know if you have looked at this, but you can also upgrade the voltage regulators (unless they are already upgraded). I have used the Sparkos discrete regulators in several applications and they are just excellent. Much faster and smoother than monolithic 78xx/79xx regulators and they also shield noise from main power supply better. I have not tested the Dexa regulators, but the Dexa are much taller and I never had the space to place them. The Sparkos are same physical size as the monolithic 78xx/79xx, but a bit thicker. The Dexa uses a NE5534 op amp for error correction. The Sparkos uses a discrete Class A circuit based on their own discrete op amps.