FYI, the NFO of that wmv starts:

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The Empire Strikes Back - Grindhouse (version 2-DCP sourced)

Welcome to our second official release, the 35mm version
of The Empire Strikes Back.

January 2015,

As a thank you to the OT community, and our fans, we are releasing another early version of the movie. We hope…

So I’m not sure exactly what this is, but it says version 2 (whereas the previous grindhouse was called “v1” within the filename I think).