If they were actually producing vaccum tubes from raw material in-house, with American labor costs and California pollution control costs, their tubes would be a lot more expensive.
Tube manufacture is nowhere near the level of toxicity to the environment that transistor manufacture is, and the world's largest transistor manufacturers are in California. Tube-making being environmentally disastrous is just another oft-repeated myth.
Still, you can't brand something as assembled in USA unless it is.
They never claimed the tubes were assembled in the US, just that the company was out of Slymar, CA. Most people mistook that for a US-made claim, and they never corrected it on purpose, even going so far as to claim their last line of Chinese 6L6's and 6CA7's were "over 90% US content" because they bought the plate material from Richardson Electronics' liquidation of the old GE/Ken-Rad plant in Owensboro, KY, never mentioning the tubes were actually made in China.
If they were deceiving anyone, you would think the FTC would have caught them long ago.
What they did was not exactly legal, but they're so small potatoes that the FTC didn't care.
