Vote for release of this title on DVD at TCM
At the Turner Classic Movies website you can vote for DVD release of movies that are currently unreleased. As the website says, vote “[b]ecause we’ll routinely send your votes to major Home video distributors responsible for releasing classic movies on to DVD. So go ahead and vote and let your voice be heard!”
Vote here for the release of El Cid.
http://www.tcmdb.com/title/title.jsp?stid=492202