over the last few years he has had some well-healed clients ask him to build them ne plus ultra amps. In the process of meeting their desires he discovered new ways to improve the DNA line.@hifiman5 and @joecollege are correct, the SMc upgrades have significantly improved over the years due to Steve's work for clients seeking the best possible amplifier he can build. I wouldn't be surprised to see him develop and bring to market a new amplifier independent of the McCormack upgrades, as with his VRE-1C preamplifier.
Currently, about the only things they reuse from the DNA amplifiers when performing upgrades (assuming the client chooses the higher/highest level of upgrades) are the chassis, heat sinks, and transistors. They can reuse the transformers but prefer to replace them with Plitron low-noise transformers. They actually don't care whether you send them non-working DNA amplifiers since they can replace everything except the heat sinks and chassis.
The project they are currently working on for me will indeed include new custom engraved faceplates that will match the faceplate on my SMc preamp. They offer a variety of colors and engraving options, to meet the desires of their clients.