If you go into the 'Media Archive' Files of this very website (see within the titles ribbon, above), there is a 'History of Ultravox' link, which gives access to a history of Ultravox up to and including the recording of the Vienna album, as compiled from a series of interviews with Warren Cann, the band's drummer and electronic percussionist. Page 34 features Warren recounting his use of the CR-78 after aquiring one at some point prior to the recording of the Vienna album. You may find some help for your essay within the contents.
I'm not sure how you'd go about contacting John Foxx. You may find some success by searching for Steve Malins of Random Music Management. Steve is John's manager (presumably, he still is) and may be able to assist you further.