I found these vintage pearl necklace for very little, when I got them home to restring & knot, I looked at the clasp, I noticed the M with the shell around it. I have a Mikimoto brooch and recognized the mark. But the there are so few knots...is it really a Mikimoto? It is vintage. Why so few knots? (Someone else said that was the Japanese method) but I have only seem Mikimoto photos with all knots.