Not that easy....
Hi Lens.
Although I cannot answer the question directly I would suggest that you write to the main organisation that deals with the Koryu groups in Japan at this address;
Nihon Kobudo Shinkokai
3 Kojimachi 6-Chome,
Chiyoda-ku, Tokyo 102
Japan.
They my be able to help you out and may give you a lst of those Koryu that are associated with them (This however is NOT all of the existant Koryu...).
Otherwise maybe the Koryu Bugei Daijiten could provide some answers altough again it will not be easy if your Japanese is not good. (And again the Daijiten rarely includes dates on timelines and so is hard to ascertain whether the arts are still going...).
Sorry to not be of more help.
Abayo..
Ben Sharples.
智は知恵、仁は思いやり、勇は勇気と説いています。