Company relationships are not part of the "Handelsregister" except it is a subsidiary company, which is unlikely as the "Rolf Lang Dresden GmbH" is clearly named. Also the "Elektronischer Bundesanzeiger" clearly states regarding the Rolf Lang Dresden GmbH: "Die Gesellschaft ist aufgelöst. Die Gläubiger der Gesellschaft werden aufgefordert, sich bei ihr zu melden." [The company is dissolved. Creditors of the company are requested to contact the company.] as of January 22, 2019.
However, the website of Rolf Lang does not state the full company name except in the title. The imprint lacks this information and the name of the managing director (even though they are legally obliged to name both). Therefore, they might have changed the name of the enterprise unknowingly.