It may be worth a note in clarification about the two styles of gunpowder flask used in Oman. Not withstanding the pre prepared charge styles shown above the two flasks have a different role... The wooden box type is for the main charge down the barrel. The more delicate silvered item shaped like a new moon is for the pan. Influence from Portugal or Germany may be included in the wooden box form whereas Ottoman style appears to reflect in the silver item. I also placed items on the Miscellaneous Forum in this regard.
See
http://www.vikingsword.com/vb/showthread.php?t=15083 at #15
and 16...the latter which may be Omani or Ottoman.