I was told by the owner of AudioSource (or whatever the name of the real audio place in Keene NH that is not Interface (whose owner is also a font of information)) that Nikko's real business was circuit breakers (hence the circuit breakers rather than fuses in Nikko products). Nikko's collapse was a result of the death of the owner and a squabble between the children, and the division of the company among them. A pity, since as all the posters have noted, their audio products were good to excellent.
I think on the east coast at least, they suffered from being thought of a Tech HiFI's house brand. But the seperates I had a while ago, and the 819 reciever I have now are more than respectable -- I was in the process of trading in one of the Alpha amps for a much newer Hafler when I realised the Hafler didn't sound better, and might have sounded worse.
By the way, I think the company that specialised in ceramics was Kyocera -- Kyoto Ceramics. But I might be wrong.