1962 R12R low volume

[journeyman]

I picked up the 1962 R12R from my amp tech today and the volume issue seems to have been solved. All filter caps were replaced and a couple of smaller coupling caps that had drifted. He did open up the front end slightly by changing one cap value. I'll have to write down what he did so I can remember. It sounds very close to my Mercury M-12; maybe a tad brighter. Of course the on-board reverb is nice to have but I'm finding it a bit weak. If I could get more out of it and somehow darken it up a little, I'd be very happy. There was a lot of dirt, dust and nicotine inside the amp and I'm wondering if I should take the reverb tank out and open it up. It seems unlikely that that could be the problem as it is almost a closed environment.

Does anyone have suggestions for reverb tweaks or troubleshooting on this R12?