Adventure in the Hopfields was actually filmed in the summer of 1953 and released in 1954. The 16mm copy that was found in a skip is not the only copy, as the Children's Film and Television Foundation (formerly the CFF) have a 35mm copy in their archives as they have a 35mm copy of most of their films. As far as I know, the BFI also have a 35mm copy of Adventure in the Hopfields. However, as with most CFF films, there is little hope that they will be released on DVD as the CFTF don't think their would be a market for them these days. I think they're wrong, though and that they should give it a go. A very few CFF films, such as The Boy Who Turned Yellow (1972) have been released on video and / or DVD in the past, but apparently didn't sell very well. I think Carlton now own the DVD rights to them, as they were originally distributed by Rank.