25 Fr. Red Cross block of four as correctly franked multiple franking on registered special delivery letter with special cancellation SAARBRÜCKEN IBASA 23.4.50 (2. strike on block of four from 29.4. ) to Saarbrücken-Schönbach with arrival postmark on the UMMER over SAARBRÜCKEN 2 30.4.50, small margin traces, very scarce multiple franking, photo expertize Hoffmann BPP