While the El Toro release may well include what you say, as I understand it, any tracks not first released in the UK until 1958 will not be PD here until 01/01/2009. So this would apply to tracks on the Buddy Holly and Chirping Crickets albums that had not been released on 1957 UK singles.
So I'm not quite sure how El Toro do this unless either they are unaware of the above or are in a slightly different copyright regime in Spain.
Dave Penny - I know you visit here sometimes - you probably know the answer to this. Am I wrong?