I am not suggesting ARC go mass market, but may be they should consider some diversification. Do they make a headphone amp? How about they emulate Manley and offer some pro oriented equipment. When studios switched to digital recording/mixing the demand for tube equipment skyrocketed. If you can design a low noise phono stage, I would think you could design a microphone preamp. Tube compressor/limiters are a thing. Even a small format line mixer should be doable. How about a tube guitar amplifier? Somebody has to make the most expensive guitar amplifier.
Alternatively ARC can continue to do exactly what they have been doing. True they keep changing ownership and right now are in receivership, but may be that has nothing to do with what they sell.