@georgelofi
Solen = SCR = Axon. Axon is essentially the middle of the road Solen for half price. Focal and others do seem to source their caps from them.
However, I would only use an Axon as a bypass. The middle to low end Solen’s are, to my ears, easily outclassed by the low end Mundorf’s and Clarity caps.
I’ve heard good things about the latest high end Solen’s but I really don’t wish to play around with them. Your mileage and ears may vary.
Now other brands, who knows. Winding machines are expensive, so if you can get cheap caps with your brand on them and get someone to put out a few positive reviews for you then you may indeed make a few bucks.
Now, what's absoultely best is if you can find a capacitor brand that costs $1/cap or less and sounds best to you. I hope you find that for yourself.
Best,
Erik