mettelus
 
Playability is better than when I first got it! Very smooth operation all around - no jumps in volume at all, and even higher ranges of gain didn't cause issues. I put it on 100% RMS and played through the 0db jack for about an hour and is astounding. The first time I have really used this amp since I rebuilt my guitar in 2012 and they match extremely well. Sustain till the cows come home and the rumble of a tube amp is just "awesome." It plays better than I ever remembered, so I will hold off on tubes for the time being - they seem to be perfectly fine, but the pots were definitely in need of TLC.
 
Again, thank you to all who took the time to help me out. This was the first time I ever did this and it went very smoothly. Your time is most appreciated!

 
To be honest, unless a tube shorted out, the glass cracked and let in air, or the cathode heater died on me, I've never really had any issues with tubes going bad from age.  I opted a few times to buy new replacements and there really wasn't a noticeable increase in anything. I thought there was until one day a few days later I pulled the tubes and accidentally got them mixed up with the originals..... nope... not a bit of difference.   I have a Mesa Boogie and it's the same deal there..... the amp is about 35 years old and the same tubes are in it now as when I was gigging and it sounds just as good.
 
Yup...save your money for some new strings because yeah... THEY do make a noticeable difference.