-US version released in 1957 by Distributors Corporation of America. Features some additional Japanese-shot footage (presumably from the Japanese workprint the US version was edited from),
As good a reason as any to bump this thread....
I'd like to call "not so!" on this one. The source for the claim that the DCA version of "Rodan" contains additional Japanese-shot footage seems to be an article, written by Brian Culver, that appeared in the Kaiju-Fan magazine sometime in 1998 (http://www.historyvortex.org/TohoAmerica2.html). This article cites several instances of footage unique to the American version, however, the last time I had my Classic Media disc of this film out, it was quite apparent that all instances of claimed "unique" footage were, in fact, existing shots that had been optically zoomed in, flipped, or otherwise manipulated.
Additionally, they wouldn't have come from a workprint, even if there were actually new scenes in the DCA version. A workprint is a print of each camera roll, used to assemble the final edit of the film. Once the workprint was finished, the original camera negative rolls would be cut to conform to the finalized workprint. Along the way, the workprint would've acquired quite a bit of wear and tear, to say nothing of grease pencil marks, tape, etc. In the early days of Eastmancolor (i.e the mid-fifties), it also wasn't unheard of for workprints to have been on b&w stock. A workprint certainly wouldn't have made an acceptable element for Toho to print off an element to send DCA, especially with the quality of the early Eastmancolor duplication stocks. Toho would've sent DCA an interpositive (a print from the camera negative with the same low contrast and orange mask as a camera negative, used for printing subsequent internegatives, i.e. the final DCA negative), or separation positives (three low-contrast positive prints, one for each color layer of the negative... yellow, cyan, magenta, which would then be printed to a final single internegative), but certainly not a workprint.