Gun control in Germany originated with the Entente Powers and the treaty of Versailles. The objective was to "demilitarize" Germany and the dragnet included weapons owned by civilians. Initially, the state did little to enact the law, indeed there was little they could do because there was no registration mechanism for firearms until 1928.
During the 1920s, the emergence of extremist paramilitary organizations caused concern within the Weimar Republic, leading to a new law in 1928 which demanded gun registration and enabled permits to be issued for a range of activities, to include buying and selling guns. The 1928 law also provided an "easy permit" mechanism sponsored by the automobile associations for any car owners who frequently had to drive in the countryside. Permits could only be issued to "... persons whose trustworthiness is not in question and who can show a need for a (gun) permit." Ironically, that precise language was exploited by the Nazis to prevent Jews and other "undesirables" from owning weapons.
After the Nazis ascended to power, new gun laws were rolled out in 1938 which drastically reduced the constraints on gun ownership:
- The 1928 law applied to all weapons but the 1938 law focused solely on handguns and exempted any long-barrel weapons from the permit requirements. Essentially, the 1938 law completely deregulated the acquisition and transfer of rifles and shotguns, and the possession of ammunition.
- Lowered the legal age for gun ownership from 21 to 18.
- Removed all gun ownership restrictions from a broad swathe of society including holders of annual hunting permits, government workers, and National Socialist German Workers' Party members (prior to the 1938 law, only officials of the central government, the states, and employees of the German Reichsbahn Railways were exempted from the gun ownership rules).
Bottom line is that gun ownership was pretty common in Germany throughout the period. At no stage were guns ever forcibly removed from the population. Thus, I think the perception that only very few people owned guns is mistaken.
I can agree with this part of the statement. No amount of pistols or hunting rifles will deter a military force equipped with tanks, armoured cars, and air assets.