Brahmserud

Hello guys! I haven´t written anything in here since the early naughties but now my comeback will kick off with a humble query about two specific arrangements; as performed by the City of Prague Philharmonic and included in the Silva Screen 6 CD box "The music of John Williams - The Definitive Collection" from 2012. I´m referring specifically to the extended versions of "Double Trouble" and "A window to the past". To my ears these two specific pieces sound like typical (and very thoughtful) JW "re-writings" in the same manner that he often creates for concert use but I can´t find any information anywhere about how or when (or even by whom) these are made. Are they JW originals or has some other composer/arranger masterfully arranged them to their new expanded (and as far as I'm concerned much more fulfilling) versions??? If they´re not from JW I´d love to meet the person behind them because (in my humble opinion) they blow their respective soundtrack counterparts clear of the water. Thoughts about this anyone?