Congrats to your purchase. Although made in Germany they are quite rare.
About the ERMA factory:
https://de.wikipedia.org/wiki/Maschinenfabrik_GeipelWhen searching for sites in a foreign language in Germany I have the option to have the contents of the site translated into German. That probably works vice versa.
Erma 22 rifles and pistols are of very good quality. A friend had a Model EG 71 in .22 l.r. The quality equals the one of a Winchester 9422.
Unfortunately there are almost no informations even in Germany about that gun.