Boussu to Rouen in 1919

This cover was sent from Boussu to Rouen in France on 6 October 1919. It sports stamps from four different series, the 10c+10c Red Cross stamp of 1915, the 1c and 2c definitives of 1915, the 2c+2c Red Cross stamp of 1918, and the 10c King Albert in trench helmet of 1919. The latter stamp had been issued a few months earlier while the Red Cross stamps were about to be taken out of circulation.

Characteristics: Stamps from four different series, incl. 2c+2c of 1918 Red Cross series Total franking = 25c (exact franking) Foreign destination but not exotic Cancel of arrival on back (?)
Estimated value: $80 [Auctioned by Olivier Simons in February 2006]