CH 1939 B2 Pro Patria FDC with address

Switzerland 1939 B (Swiss National Fête and PRO PATRIA - issues)
Laupen Castle, SBK B2, Michel 356,
FDC with address to Schweizerisches Bundesfeierkomittee in Zürich,
2 stamps (pair) cancelled "15.VI.39 Schweiz. Postmuseum BERN", luxury quality.