I use to see Blackie at the North Carolina Gun Collector’s show in Charlotte, NC. My best friend Ed Cole knew Blackie well and owned several of his knives. Ed carried a very nice Collins fixed blade skinner deer hunting for 15-20 years until his wife gave him a Randall Bird and Trout.
D2 and ATS34CM are good tuff edge holding steels- they take a very good edge when heat treated correctly. Sharpening them is not the easiest but not the hardest either.