1828 x 1556 is the resolution at which the '04 scan was likely done. That's 2K for cinemascope, the format in which the OT (and, for what it's worth, TPM) was shot. Multiply 1828 by the 2x anamorphic squeeze of the lens and you've got 3656 x 1556, a 2.35:1 ratio. Or, if you'd like, simply cut the horizontal resolution in half and you've got 1828 x 778, also 2.35:1. Since the raw scan itself is only 1828 - less than even full 1920 HD res, nevermind 2048 - I guess some kind of magic is worked. Beats me.

Anyway, I had a couple paragraphs typed up about how the o-neg is probably still in its '97 conformation (despite how I'd love for danny_boy to be right), but this stupid ipad had to go and refresh the page after I opened up another tab to look up the exact numbers I just posted. Ugh, I gotta get a new laptop at some point. Anyway, to quickly summarize, Jim Ward said in '04 that they went back to the original negative for the dvd (the lowry master that was also used for the blu-ray). He said that the previous transfers were from IP and even specified that this meant "one generation off the negative." So, if the o-neg was still in its original 1977 conformation, it wouldn't have made much sense for them to scan it in and then meticulously "respecialize it." They might as well have just scanned the '97 IP if that had been the situation.