Very rare version of the Junghans J56 with regulating system on the regulator lever. It is not certain whether this version was manufactured by Junghans.
The numbers on the movement refer to the following patents:
US Patent US2542430 Self-Regulation.pdf
US Patent US2858029 Self-Regulation.pdf
Many thanks to D. Rüdinger for the pictures of his rare version!
The automatic version is also presented on the company's own museum Junghans in Schramberg and is designated as a Junghans J55. Further information on cooperation with Westclox: The Westclox-Mystery