CH 1943 W12-W13 stamps out of bloc Zurich 4+6 FDC with address

Switzerland 1943 W (Semi-postals and Special issues sold at an additional premium)
stamps out of anniversary bloc "100 Jahre Schweizer Postmarken Zürich (Zürich 4+6)",
FDC of bloc cutouts on white cover address (letter of Marken-Müller), with additional Pro Juventute stamp,
cancelled with special red first day cancellation "26.II.43 Zürich - 100. Jahre Schweizer Postmarken", luxury quality,
Catalog SBK W12-W13 and J104, Michel 417-418 and 415.