After graduating from a commercial college in Vienna, Rudolf Prinz worked as an accountant in various companies. He served for a few months in the First World War and in 1921 opened his own antiques dealership at his home address at Chwallagasse 2/II/10 in Vienna's 6th district. In 1922 he moved to Florianigasse 44/5 / Schlesinger Platz in the 8th district. Prinz was an "Alter Herr" (alumnus member) of the German nationalist duelling fraternity Germania Wien and joined the NSDAP and the National Socialist People's Welfare (Nationalsozialistische Volkswohlfahrt) organization in March 1933. He continued to be active in the NSDAP while it was banned during the period of the Austrofascist corporate state and was imprisoned for fourteen days in 1937 for that reason. He registered again with the NSDAP in May 1938 under membership number 6.301.514 and also joined the Reich Colonial League (Reichskolonialbund) in 1939. After running his antiques dealership for a short time in 1937 from Lange Gasse 53 in the 8th district, he moved in November 1938 to empty premises at Josefsplatz 5 in the 1st district. He states that it had previously been a dressmaking shop. In view of his increased sales, Prinz was ordered in 1942 by the commercial court in Vienna to enter his company in the register of companies. As he had been conscripted into the Wehrmacht with the rank of first lieutenant (Oberleutnant), the registration as a sole proprietorship did not take place until 1943.

In July 1945 he registered as a former National Socialist. Because of his close business relationship with his sister Karoline Nehammer and her business partner Oskar Hamel, who also worked in the arts and antiques business, the public prosecutor's office charged Prinz, Hamel and Nehammer jointly under section 6 of the War Criminals Act (Illegal enrichment). They were accused of having acquired valuables cheaply from persecutees after the annexation of Austria to the German Reich. Prinz's assets after the war consisted primarily of antiques, and he had moved most of his stocks to Ernstbrunn in the Weinviertel (Lower Austria). In September 1945, Vienna municipal department 69 appointed Stefanie Tintner, an employee of the company, as public administrator. The criminal proceedings were closed in July 1946, and in 1947 the Federal Ministry for Securing Property and Economic Planning released the stocks seized in 1945 and stored in the Dorotheum in Vienna. The public administration was lifted in March 1948. Stefanie Tinter had been instrumental in Prinz's exoneration and was subsequently designated by him in his will as heir to his estate along with his son Hans and his granddaughter. After his death in October 1948, the company was taken over by Hans Prinz, who was required to submit an affidavit stating that he was not on the list of persons under the 1947 National Socialist Act. He sold the company in 1980, but it was not deleted from the register of companies until 1992.