Hugo Hengstenberg leather patcher
You will find logo That will look the same. Some with D & S or S & H or just the D or H.
Carl Schmidt & Nikolaus Dürkopp started out together after they left Carl Baer & Heinrich Koch and designed their own machines. Later on Carl Schmidt left Nikolaus Dürkopp and worked with Hugo Hengstenberg. And finally Carl Schmidt left Hengstenberg to work for Singer company. Confusing ?
Baer & Rempel (Phoenix), Koch & Co, Dürkopp & Schmidt, Dürkopp, C Schmidt, C Schmidt & Hengstenberg and finally Hengstenberg & CO (later changed to Anker-Werke AG), Dürkopp & Adler. It all started in Bielefeld... Sole survivor today is Dürkopp.
I do stand corrected if any one else jumps in here.