Some people have said that it's "new computer smell" and that it's "not that bad". I disagree.
It reeks!
I've opened many many computers, both back in the 80's and NOS stuff over the years. Nothing smelled this bad - and I own an Amiga 1000 that somebody's cats pissed all over. My VT100 has a faint smell that is a bit similar to this (and I thought
that was toxic), but this is on a whole new level.
The smell seems to be coming from the plastic, not the internal components. The NABU was made in Korea and maybe the Koreans hadn't yet perfected the art of making non-smelly plastics at the time. That's my theory. (I plan on producing a scientific paper and the Nobel Prize could very well be within my grasp.)
I only hope the terrible smell disappears over time. (...maybe another 40 years or so)
Edit: Ah, I see you did mention plastic parts from Korea. (but that doesn't mean I'll let you share my Nobel Prize

)