Thank you for posting this. Its always nice to see very unusual items on the forum and this certainly is not something seen everyday.
My knowledge of these is more or less limited to the photos I've seen in various National Geographic articles or in documentaries.
The pattern in the wood of the bow is very aesthetically pleasing and it certainly looks like it has an incredibly heavy draw as you note.
I've always found the very long arrows of these cultures interesting but had never really heard what the reason for the design was. Thanks for sharing your thoughts on that as well.
Bows are something that seem to be rarely collected, yet were/are the some of the most common ethnographic weapons in use.
Again, thanks for sharing it here and congratulations on acquiring this piece!