My first thought was
Machine Doubling as well. However the first "1" looks like it has distinct separation between the two "1"s. I'm not sure if you can do with with
Machine Doubling. It also looks like there might be separation on the "9" as well. The last "1" screams MD. The "3" not so much. I would be most interested to learn how you can have separation between elements in MD.
On the whole I'm leaning towards MD; as you say the whole obv shows it. I just can't get it out that it might be MD and a DD. Lets here what the others say.