The complete set in detail

S050
SG No. 50
1921 - Germania : Overprinted 'Saargebiet' and new value - 20 Pfg. / 75 Pfg. ; black and blue-green

S051
SG No. 51
1921 - Germania : Overprinted 'Saargebiet' and new value - 5 Mk. / 15 Pfg. ; carmine-brown

S052
SG No. 52
1921 - Germania : Overprinted 'Saargebiet' and new value - 10 Mk. / 15 Pfg. ; carmine-brown