It also seems to have played Pittsburgh as a roadshow in October 1967. It appears to have played six weeks in Pittsburgh, closing in late November. In late December 1967, it returned (probably cut) with continuous performances.
THE DIRTY DOZEN was filmed flat (1.75:1 hard matte, I believe), but had 70mm showings. But were they reserved seat showings? I don't think so.
And what about the 1967 re-issue of GONE WITH THE WIND, which was blown up to 70MM? Did that play on a reserved seat basis anywhere?