http://buyee.jp/item/yahoo/auction/l385309639
M2-1028 Rollbar. Looks to be complete with padding and upper bars. Brackets and hardware, too (I'd find some new bolts and nuts, for sure).
I find it amusing that Buyee will let me bid on this (which I can only imagine would be a nightmare to ship) but not the Watanabe B-types that I wanted to badly a few days ago...