There were a few qualifying matches before the actual tournament. According to the Hamburger Abendblatt, the Japanese Jun Kamiwazumi won against Lutz Jelitto and according to the magazine Tennis there were at least the following results: Julian Ganzabal (Argentina) - Rolf Gehring 6: 1, 6: 3; Harald Neuner - Shimamura (Japan) 6: 3, 6: 3 and Terry Ryan (South Africa) - Lutz Jelitto 6: 4, 3: 6, 6: 0. Whether Jelitto really had two chances to qualify for the tournament remains to be seen.
Tennis, official organ of the German Tennis Federation , Volume 26, Issue 13 (July 1st 1973 issue)
Note: For some results there are slight deviations between the Hamburger Abendblatt and the magazine Tennis. If you compare the results with those on the ATP website, there are even more differences.
↑ Nikola Pilić had been banned from his association for not taking part in a Davis Cup match.
↑ Result according to the ATP website, which is perhaps a very good compromise between the Hamburger Abendblatt result 6: 1, 6: 1 and the magazine tennis result 6: 2, 6: 2.
↑ The second and third movements according to Hamburger Abendblatt 6: 3, 6: 4; according to "Tennis" 6: 4, 6: 2; according to the ATP website 6: 4, 6: 4.
↑ The second and third movements according to Hamburger Abendblatt 3: 6, 6: 3; according to "Tennis" 1: 6, 6: 2; according to the ATP website 3: 6, 6: 2.