Please don’t misread what I said. I only said that I felt that the DWM 487D was loaded in the late 1930s based on the headstamp letters and primer seal color. I do not know when it was developed. Perhaps then, perhaps much earlier.
The DWM 487A I have not really seen except briefly, shown one by the lucky, but now impoverished, recipient at a big cartridge show. I recall that it has Serifed letters, making it much, much earlier than my 487D round.
I know nothing of the 487B except what I have read, because I don’t know a single person who has ever seen a specimen of this round. In my mind, it is likely it was never made. Not everything in the DWM case register was necessarily manufactured.
The 487C, the 9 x 19mm case type, was made specifically for the Model 1912/14 Mauser Pistol. I had one of these pistols years ago with a two-digit serial number. am too tired from setting up a cowboy shoot today to go downstairs and look up the number in my files. However, it has appeared in books and is one with the word Oberndorf on the side of the pistol spelled wrong - as “Obendorf.” These guns came out right before WWI, I believe, so that cartridge too, which has a serifed-letter headstamp, is much earlier than the actual production date of all the 487D cartridges I have seen (only three, ever, but the other two were just like mine).
I will try to do a scan of the headstamps today. I am tired, have house guests, my son and his family will join us and our guests briefly and then I have to drive him to San Francisco Airport. Tomorrow I have the match I set up today. Next week I will be in Southern California all week to see friends and to attend the CCCA Annual Show at La Palma. Then, when I get back, I have a four day cowboy shoot out in the central valley of California, and will not be home. So, you can see I am not making up my lack of time this month. I will do my best to accomodate you though.