Numbered cover with nice cachet and 6 coat of arms values cancelled on first day of issue Dec. 3, 1958 and mailed to Cercle Philatelique in Ettelbruck.  Receiving cancel Ettelbruck next day on reverse.  Back flap is open.  Cover has a fold on left side to the right of the cachet, not impacting the stamps.   

Catalog: Michel 595 - 600 & Scott B204-209.