Even more importantly, can we get back on the question at hand please?
From my experience, with a set proplerly restored (red velvet ropes and all), it should deliver the same or better reliable performance as when new.
I agree, 2 hours a day of use should be pretty easy on the set. Of course, there is always a lurking issue of a flyback or a resistor or two that weren't replaced acting up but I should expect it to run for several months before needing any tubes changed. I used to have a 23" Sylvania that I replaced the flyback and HO tubes in and the thing ran 4-6 hours a day for two years until the back fell off of it and sliced the neck of the CRT. Oh that hurt to see and hear. Yes, I know, I should have secured it better. Live and learn, but that was 20 years ago.
Until that time, it worked like a champ so from a quality set like a Zenith, it should play for a good long time between touch ups.
