We know Marvel has reproduced Captain America’s WWII leather jacket costume for the movie, and back in April ComicBookMovie posted pictures of a 1940’s scene that was being filmed. At that time it was speculated that it was just a flashback, but now more information has come out about the scene that points to something different.
ComicBookMovie has learned that in addition to Chris Evans and Haley Atwell, another Avenger was present:
Anyhow, regarding that ballroom scene filmed in London, Hayley Atwell and Chris Evans were supposedly joined by Paul Bettany, who plays The Vision. What do you think?
Having the Vision travel back in time would tie into the rumors that the Time Gem plays a big part in the story. One of those rumors says that Ultron creates a time loop in which Tony Stark creates him an army of Vibranium soldiers (as seen on the Entertainment Weekly cover).
This is just speculation, but if Ultron is abusing the Time Gem in the present to create his “Age of Ultron”, it’s possible The Vision uses it to travel through time to recruit a younger Steve Rogers to assist in defeating him. That would explain why he was present at the filming of a scene set in 1940…