Yes, these flasks are rather similar to flasks shown in the katalogue of the exposition of about 150 powder flasks and horns in the national museum of history and art in Luxembourg in 1995
(the book can still be bought)
The head of the flasks are very similar to a powder flask from Germany around 1650, made from an antler fork.
similar scrimshaw can be found on flat cowhorn flasks made in Southern germany
I think these carved horns might have had some influence on the typical scrimshaw horns in America
(Please excuse the bad quality of the fotos)