How long should a restored roundie last?

[compucat]

I have finally found a place in the house for my not-yet-restored Zenith roundie to live. I plan to get a DVD recorder with ATSC tuner built-in so I can put into daily service and be ready for the digital switchover. Once properly restored, how long might I expect it to operate between repairs? I'm not looking for any guarantees, just curious about the meantime between failures of early color sets. For the purpose of this inquiry, assume the following conditions:

1. Zenith 1965 tube Tv - Chassis 25mc33
2. Picture tube with full emission on all guns
3. New tubes in Horiz. out, Damper, HV Rect and HV Regulator circuits
4. Horizontal cathode current set to proper level
5. No more than two hours average daily usage
5. Adequate ventilation
6. Plugged into surge protector
7. Electrolytic caps replaced
8. Some really cool rabbit ears
9. Velvet ropes to discourage touching by unqualified hands

How often do they need touch ups of greyscale, convergence etc. I don't expect they are as maintenance free as modern sets. I'm just wondering how often I might need pull the back off once I start putting it into real life service - not just for display.