The Del Rey editions use Howards original text not the versions that appeared in the pulps. I'm guessing the version you have David does not have all the fragments that are collected in the Del Rey editions. Again these are fragments not complete stories so none are finished up by other writers. Which was the norm with the old paperbacks.

Here is a 8 page disscussion upon that collection from the Robert E Howard boards: http://www.conan.com/invb....php?showtopic=6747&st=0