Sounds like it was made by the company that is now called Helko.
...the Crown with CH is Carl Helsper, Wuppertal-Küllenhahn...
Carl Helsper exists today as Helko....
...
About Helko:
"...In the early thirties, a partner named Kotthaus joined the enterprise, and the company became known as helko (helsper / kotthaus). When helko took over the Carl Helsper Werkzeugfabrik in the early sixties, the complete company name in the German Register of Commerce became Carl & Aug. Helsper GmbH & Co., KG, helkowerk. Since then, the company has continued to improve the quality of its products, and helko axes and hatchets are now recognized worldwide as some of the finest woodworking tools available.
"helko axes and hatchets are crafted to meet stringent German DIN manufacturing standards (DIN 7287, 7294, 7295, 5131, and 5132). They are then safety proofed by German testing institute Versuchs und Prüfanstalt Remscheid (VPA), and permitted to wear the VPA/GS label.
"In accordance with DIN/GS directions, the hardness of helko axe and hatchet edges is between 47-56 HRC (Rockwell) up to 30 millimeters from the cutting edge, while the eye is generally left unhardened to prevent cracks in the steel. During the manufacturing process, the axe heads are hardened and cooled down in an oil bath prior to being heated to about 400° Celsius. This relieves strain on the surface of the steel after hardening, and provides the correct level of hardness. Unlike many axes which are cooled in a water bath, helko tools are cooled in lukewarm oil in order to avoid small chinks in the material. Afterwards, the tools are sandblasted to remove oil residue from the surface prior to grinding and painting..."
quoted from helkonorthamerica.com
(Note: The 400 degrees sounds right, but they must have forgotten to label it Fahrenheit instead of Celsius.)