Wonderful gear, but the bar doesn't need to be that high. Most of the tuners we need to align are limited in the precision of their adjustments. Certainly there are some TOTL tuners where something like an ST1000A is inadequate, but I'd never discourage somebody from learning how to do this because they couldn't acquire TOTL test gear. IMO, you also have to start somewhere, with something, to begin learning at all.
My post was not intended to discourage, but to apprise. The gear shown was to reveal that you need more than a screwdriver & desire. You need a good AM/FM/Stereo signal generator, distortion analyzer & a GOOD scope. You just do. For RF work, your stuff should be calibratible & at least reasonably calibrated.
My real recomendation was the book. It includes info on tubed gear, as well as sollid state. ST test gear is a bit long in the tooth and likely in need of restoration and calibration itself, before it can be used to align tuners. I know. I have an ST-1700B in my gear complement. They made good stuff, but there are alot of switch contacts to clean up, and solder joints to refresh, etc. Again, your gear should be at least reasonably calibrated.
It would be unfortunate to start buying alot of gear and to get stuck in the RF mud. As you know, there is more to know, and to be careful and aware of, when dealing with RF, especially with that which is to produce hi-fi output. Regardless of what gear you choose, you will need to spend significant green. When I started doing tuners, my test gear complement more than doubled, over what was needed for amps & tape decks.
Buy and absorb the book. You won't be sorry. THEN, start buying test gear. Come on in. The water is fine. But do it with your eyes OPEN. A split tuning slug would be pretty hard to find, as a culprit, without the knowledge you'll get from the book. You could very easily split one yourself, or someone could have split it for you. Ham-hands are quite common out here in the field. You can get the book much cheaper than the link I posted, if you are patient. I just wanted you to see what it looked like, and read some reviews. Your most necessary and affordable piece of test gear is between your ears. If that is tuned up sufficiently, many useful test signals are being broadcast over the airwaves for free.
Good luck,
Rich P