It is not a Bunchin.
Seems like a part used by metalsmiths for decoration of tansu or other artifacts.
Such items sometimes come up on the collectors market.
Attached examples of such..
It looks like Lorenzo is correct about the motif.
http://img01.ti-da.net/usr/bambi/P1000052.JPG
Japan issued a set of stamps on this tale:
http://thumbnail.image.rakuten.co.jp/@0_mall/timbre/cabinet/201102_007/751221.jpg?_ex=200x200&s=0&r=1