Well constructed amp, if i say so myself. Yes those are the caps. I will be delighted to hear you results, especially if there is no significant difference.
What's interesting to consider is that a crossover cap in a speaker has several amps flowing through it and large voltages across it which it is blocking from the driver. In this case the dielectric is getting run up and down all over the place. In addition, series resistance can be significant. Both of these have large sonic consequences and replacing electrolytics with mylar or polypropylene makes good sense.
In contrast, grid coupling caps have no signal across them (they are a short for the audio range and beyond). They also have virtually no audio current through them (micro amps vs amps in a speaker). All they are doing is blocking DC. Now I would like someone to explain to me why we care who made, from what exotic materials, a capacitor that is doing close to nothing as far as the signal is concerned.
I customer of mine spent $600 (just for the parts) replacing the caps in his RM-1. He was not sure he could hear a difference. Besides that, they didn't fit.
