@oriole, I've had a look through my collection and found that I already have the following figures covered:
Charlemagne - Grödig, 40 Heller (1920)
Maurice Wilhelm, Duke of Saxe-Merseburg - Merseburg, 10 Pfennig (1921)
St. John of Nepomuk - Schlierbach, 50 Heller (1920)
Otto I, Holy Roman Emperor - Magdeburg, 50 Pfennig (1920)
St. Peter - Trier, 50 Pfennig (1918)
Friedrich Sertürner - Neuhaus (Paderborn), 2 Mark (1921)
Louis Spohr - Braunschweig, 25 Pfennig (1921)