Nikkatsu action films + Asia-Pol

[Jordan A. Yamaji Smith]

Dear KJ folks,

I'm passing along a question from a colleague in Chinese film, whose question I'm afraid I didn't have much of an answer for. 

He was asking about spy films in Japan during the Cold War, or more broadly speaking, the developing supergenre of ‘action’ films.  He's read Mark Schilling’s No Borders, No Limits on Nikkatsu action films, but is wondering what else in English is worth reading on the Nikkatsu action films.
  
He is also wondering about a Shaw Brothers – Nikkatsu coproduction: Asia Pol (dir. Akinori Matsuo, 1966).  We have the Shaw DVD, with Chinese dialogue, at UCLA. It seems there was also a Japanese-language release, either a parallel version filmed simultaneously with alternate (Japanese-speaking) cast, or simply a dubbed version.  Anyone know if the Japanese version is available anywhere?  (Or: where should he might look?)

Thanks in advance for any leads,

Jordan Smith