There is no recorded acknowledgement of the use of the GB design nor of any dispute by GB!Was there some some sort of "gentleman's agreement" here?
Many did and copied the Jahresuhrenfabrik clock exactly. took their time and commenced production of a Harder patent 400-day clock in 1902.
Thus ended the 30 years of 400-day clock production by Gustav Becker, a man, and his company, who had more to do with the design and production of the 400-day clock than he is given credit for.
Gustav Becker (1819-1885) was a dedicated and successful German clockmaker.
In 1885, Gustav Becker died, but such was the reputation of the company and products that business momentum carried on right through until 1926 when GB was absorbed into the Junghans Company, who continued to market clocks under the GB brand until 1935.
Gustav Becker is what might be called a "quiet achiever" as there is substantiated evidence that he developed a 400-day clock and tried to commercialise it as early as 1875.