The Japanese disc is the longer cut,(i think)
the Jap disc is definately the shorter version, unless it has come out as one of the new SPO releases with a different version (which is possible)
Mine is the SPO disc which i've had for about 3 years and on checking its running time is approx 107 minutes which concurs with the uncut running time stated in Howard Hughes book and includes all the missing footage stated including the duel between Brad and Beau,the shootout between Bennets Raiders and a posse outside the De Wintons mansion,the conversation between Max's sister and Brad,the full woodland shack scene,the full bank heist and all dialogue that was either clipped mid sentence or totally missing in the cut 90 minute version is present and correct.
'Lo All

I've got the SPO disc too, and I can confirm that it's the longer cut. (I've got the shorter cut on video, from its Aktiv release in the 1990s; and I've also got the Koch Media box set.)
I may be wrong, but didn't the BBC's screening of the film, as part of the Moviedrome season, contain yet another slightly different cut of the film? When I bought the Aktiv tape, I taped over my recording of the Moviedrome screening; but when I watched Aktiv's release I thought I noticed some differences between it and Moviedrome's print. These differences were, I think, mostly around the beginning of the film, during the sequence in which Milian and Volonte are hiding out in the forest.
Re: THE BIG GUNDOWN.
Koch's release has a strange anomaly, about an hour into the picture; there's a short fragment of the FACCIA A FACCIA score that plays during a shot in which Tomas Milian rides away from the camera, leaving Van Cleef alone in the desert. I wondered if this anomalous piece of music had been inserted by Koch as a 'watermark' of sorts. Does anyone know for sure?
Koch's DVD certainly looks better than any other release of this film that I've seen. Speaking of which, did anyone else buy the early Spanish DVD release from around 2000/2001? I snagged it up because I was desparate to rewatch the film, having not seen it since its screening on Channel 4 in the early 1990s. The Spanish disc looked absolutely terrible and suffered from some very heavy cropping. I've also got the Italian DVD release kicking about someplace, as well as Franco Cleef's 'reconstruction'--which is my preferred way of viewing the film, thanks to the availability of the English dub.