Highest BUILD quality tube amps?

I liked my VAC Phi 200.

IMO/IME building a power amp, especially a tube amp, is best done point to point. This ensures that the amp will have the longest life. But I also find it important to have a nice build quality and appearance internally, since its actually easier to control stray capacitance, which can mess with high frequency bandwidth. Plus its nice to see that people take pride in their work. A technician's signature or initials is always a good thing to see.

25 years old Air Tight ATM3. A timer had to be replaced 6 years ago and a couple of resistors. That’s it. 12 years old Air Tight ATE2 preamp. Nothing needs to be fixed yet. 

Wavelength Audio by Gordon Rankin. I have a pair of Cardinal XS monos (300B) and Siver 45 monos first versions.

I normally find this kind of question impossible to answer, but, when it comes to build quality, I think there is a company that has a record to sustain the evidence that it is a top contender, and that is Western Electric.  There are many of its amps that are 80 to 90 years old that are still running and delivering world-class sound.  I've heard terrific modern builds using old Western Electric parts, including 70 year old capacitors and resistors.  Some other brands may, in the future prove to be that good, but, for now, I find it hard to beat Western Electric.