When were the scenes with Frodo (Elijah Wood) and the older Bilbo (Ian Holm) shot for The Hobbit? Were they perhaps shot during the making of LotR?
The scenes with Frodo, played by Elijah Wood, were filmed specifically for The Hobbit, as in within the shooting schedule for the movie, and not during making of LOTR movies.
This article mentions Elijah being excited to return to Middle Earth!
They were new scenes made for The Hobbit. Interviews with Elijah Wood show that he was excited to be back on set in New Zealand ten years after the LotR movies were shot. (I will try to find one and link to it).
Also the fact the movie was entirely shot in 48fps 3D also indicates that these are new scenes.