Miele used a lot of different BB shells including the one in your picture. What is most distinctive are the dropouts. I have never seen them on any other frame although I doubt they were exclusive to only Miele. Also the way the dropouts are attached to the stays in your picture is exactly how Miele did their attachments.

In 1995 Miele auctioned off their frame building equipment and supplies and I brought some of both back to Michigan with me. It was a fortunate trip because for years I've been able to use the materials I got there in my framebuilding classes for brazing practice. I have a 5 gallon pail full of those dropouts. That is why I am so familiar with them. I also got a bunch of lugs and shells and fork crowns. They used a lot of different kinds on their different models.