Hi Jun
I understand quite well. I've been puzzled as well and heard many variations.
The Danish Aikikai is primarily training in Nishio Aikido, and some of our high ranking senseis have lived in Japan training with Nishio sensei for years. Especially Mr. Bunzel. He deliveres information to the Danish Aikikai webpage which states the following:
8th dan Aikido
7th dan Shihan Nihon Zendoku Iaido
4th dan Kodokan Judo
4th dan Shindo Shizen ryu Karate
Trained in Shindo Muso ryu – Jodo(staff)
Trained in Hozoin ryu – Yari (spear)
Founder of Aiki Toho Iai
I believe this is from a reliable source. Heres the page (in danish):
http://www.aikikai.dk/?page_id=262
Regardless of rank - he was amazing, and my only regret is to have not fully taken advantage of the chance to learn from him while he was still alive.
JJ