Onkyo tape deck-OEM Nakamichi?

On the Naks.com website the Onkyo TA-2070 cassette deck(circa 1982-1984) is listed as a "third party" unit. I'm wondering if anyone actually knows the extenet of Nakamichi's involvement with this product?

Did they engineer it, actually manufacture it or just have some design and consulting input?

Also, if anyone has ANY info in this specific deck I'd appreciate it.
I have one and it's great but it needs service.

Thanks. Timo.