I've done three complete frame-off restorations and the lesson I've had to learn each time is that sequence matters as much as quality.

You cannot paint the frame and then do bodywork that requires grinding. You cannot install the interior and then do engine work that creates metal shavings. You cannot plumb the fuel system and then route the wiring.

The correct sequence for a body-off restoration: strip and repair body and frame separately, prime both, paint frame and undercarriage while body is off, restore running gear and driveline, reinstall body, paint exterior, install mechanicals, install interior. Every deviation from this sequence creates rework.

The temptation is to do the visible, satisfying work first. Resist it. The sequence that produces the best result is almost never the most emotionally satisfying order of operations.