From Brussels to USA in 1920

This cover was sent from Brussels on 13 July 1920 to Mansfield in Pennsylvania, USA, where it arrived some time later. It sports an array of stamps from different series. The Red Cross stamp is the oldest of all and about to be taken from circulation.
See a very similar cover with the same brown envelope, same handwriting and same destination, but sent from Etterbeek.

Characteristics: Mixed franking with 5c+5c Red Cross and later stamps Total franking = 63c (exact amount?) Distant foreign destination Nice cancellations of the stamps Cancel of arrival on the back Multiple short tears
Estimated value: $63 [Auctioned by Olivier Simons in April 2006]