Here's a "Variety" ad from Monday May 11, 1981 announcing the first day of filming.
Found it at this Ebay auction.
Deleted Scene featuring Beatrice Straight and a never before seen character!
from the St. Mark Collection
Above is a deleted scene featuring Dr. Lesh (Beatrice Straight) and her mentor at the University, Dr. Anthony Farrow. Farrow was portrayed by the late veteran actor Edward Ashley, star of many classic Hollywood films including 1940's "Pride and Prejudice" (http://www.imdb.com/name/nm0039049/). This scene featured the two characters discussing the video tapes Lesh's team filmed at the Freeling house, and Farrow's suggestion that Lesh bring in "her big guns" to help (Tangina). It also featured a bit of foreshadowing as Ashley notices something interesting that materialized with the pile of jewelry that fell from the "bilocation" point in the ceiling. While sadly this scene was cut from the film, it was featured in the novelization by James Kahn.
As to whether footage from this scene still exists, the answer is.....YES.