http://www.atma-sphere.com/Resources/6AS7G_Visual_Inspection.php
Some say the copper foil V-Caps take about 150 hours, be we experience them sounding very good right out of the box. However, with all the updates done on this set of amps, they're going to need some break-in time; as they break in they will become more lucid.
Since you're trying to nurse those old power tubes you might want to get some 3 amp slow blow fuses off of ebay or amazon. We sell them also.