pcDH,
I wish I could answer your question. I have seen Necchis such as this discussed on this forum, so if you are any good at searches you might find one of those threads. It's probably in the Vintage SM Shop thread.
Your question however begets another question. Did Necchi have a Japanese factory, and did they sell badged machines?
My Aldens Magic ZZ ( Made In Japan),
is almost identical to the Necchi (Made in Italy) in your CL add.
If I didn't know better I'd say they were made in the same factory.
Joe