I recently got rid of all my DE razors except the merkur progress, which I consider near perfect. I start out on 1.5 for first pass then .5 for x-grain for a bbs shave every time. The cheaper blades work best for me. Derby, Shark, and Freds cheap Personas. Sharp blades cut me up, so I've quit looking for better. I think the progress is near perfect, that is for me. Now I am truly saving money.
I think they are zinc alloy like the modern versions. Maybe better plating. German razors for the most part have been constructed with Zinc alloy since the 1930s with either chrome, nickel, or silver plating. There are exceptions but I think the predominance is zinc.