I just posted on the WW1 guns blog a contribution from a friend, with a German smooth bore minenwerfer ("FlugelMinenWerfer'), surviving in Belgium, near Mons.
The problem is this minenwerfer tube and wedge presents big differences with the 2 classical types of Flugel Minenwerfer I know
24cm FlugelMinenwerfer IKO :
24cm FlugelMinenwerfer Albrecht
I sometimes read about a 'late type of Albrecht FlugelMinenwerfer'. Could this one be of that type ? Who knows more about that late version ?