Not sure if it's a Show Off quality, since things I've seen here make me very humble. However... I could write a long long story, how the spring comes, and I get to ski away to remote rocks on the Baltic Sea to hunt the seals. Yes, the pics and story would be rated K-18 and tagged as "contains disturbing images" but there should be no one to judge, as it is 100% legit, and part of the culture. The balance between human-sea mammals and the fish - fisherman - all other buying the fish need some actions. So lets skip that part concentrate the "Viking" mittens.
My thoughts about the mitten patterns is that if you look your hand, its rarely flat. Sewing a mitten that you use to keep your 5fingers warm in the very cold, should be built in a way that your hand is relaxed, (Four finger on a mild arch, and thumb straight. ) So technically in the pattern, the upper fur part much larger than the palm part. And when I sew it together I push the parts against each others to make the arch for the four fingers. The arch forms to it's final shape, when they are used (Since I've here been too lazy to stretch it by pulling). As in pics they still look a bit "cubic".
99% these mittens to use. Hunters, snowmobile folks etc. Inner parts are fleece, or thick wool fabric with some added padding on the knuckle side
For the palm and thumb, I mainly use old leather jackets, sofas whatever recycled leather or reindeer skin. Top or the (Dont know the english word for knuckles side) is here home park'd seal skin.
Since my Adler is not in shape, I use eyelets and rivets to fix the final seam.