It's always exciting to see that first light on the screen.
You may be close to having a coherent picture. What are you using as a source -- VHS player, DVD player, etc.?
As you may know, wherever your TV has two tubes of the same type (say, two 6AU6), you can swap them and see what happens. If no change, then chances are that they're either both bad or both good. In restoring dozens of radios and TVs, I've found that the majority of old tubes found in those sets were still good, so the odds are somewhat in your favor.
You can also perform a simple dud/not-dud test on a tube's filament with an ohmmeter as described at
http://antiqueradio.org/FirstStepsInRestoration.htm .
I would not go nuts replacing marginal resistors at this stage. If one is WAY off or totally failed, then replace it, but consider that many parts of your TV are working "purty good" if you're seeing a lit screen. Going overboard with mass replacements creates more opportunities for mistakes. As earlyfilm noted, it's worthwhile to do the systematic tests and record the results in any case.
At this stage, I would focus on getting an image on the screen along with audio. Then you can do selective troubleshooting.
Good progress so far!
Phil Nelson