| Switzerland - XX | 1931 (19 June). Luzern - Germany. Reg reimbours airmail private card. Air multifkd / special cachet 35c + 40c. Basel + Frankfurt flight connection. |
U$ | 160 |
| Switzerland - XX | 1931 (19 June). Luzern - Germany. Reg reimbours airmail private card. Air multifkd / special cachet 35c + 40c. Basel + Frankfurt flight connection. |
U$ | 160 |