a pair of josef seibel boots that are not sold in the US.
For that label, I'd try it at Salamander or HUMANIC, both in the Karonlinenstraße (which is actually the most important shopping street (1); it branches off from the Königsstrasse to the west at the St. Lorenz church - there are also the above-mentioned Breuninger and Wöhrl). Another possibility would be Schuh Hoffmann (aka Schübel-Schuh) at Hallplatz No. 5, an outwardly unattractive store, but stocking rare brands. BTW, a Mephisto shoes store ist at Königsstraße 29, next to the Peter Hahn store mentioned above.
(1) the others are: Königsstraße, Kaiserstraße, and Breite Gasse, all close together in the St. Lorenz quarter.