1942-S -1-DO-001, 1942-S-1MM-001

Not a die variety at all...unfortunately it's Machine Doubling, just as MorgansRmine stated. It is good, though, that you picked out that the attributes of your coin do not match the doubled die. That's a start. Just remember, if the doubling isn't exactly - EXACTLY - what you see in the photos, then you have the wrong variety picked out. It's kind of akin to saying, "Well, this truck has to be a Ford because it's red, even though it says CHEVROLET on the tailgate. I'll have to ignore what it says and call it a Ford because it's red." You wouldn't believe the number of people who call their coins one thing because one of 10 different attributes or markers matches. In the case of doubled dies, ALL 10 have to match.

To chime in, I think this is a very important point which I eventually learned and applied towards finding IHC varieties. On the upside, this fact helps us narrow down the variety or ultimately dismiss as damage. I suppose everyone looks for varieties differently...I tend to reduce a variety to a set of datapoints which must be present for each variety, where each series is unique in regard to requirements. It's actually helped me detect varieties from photos which seemingly lacked enough details. Just agreeing here.