What is the AMNH collection?
I'm probably confusing you a little bit. When we're talking about the northern eurasian bow, we're actually talking about bows from an area the size of continental USA, with change. With the wording "Fenno-ugric" I think one looks more to the bows to the west in this area. There are of course variations in bow design from such a large area, containing numerous different bow hunting cultures, and languages – same bows are 7 feet tall, others are 4 feet; some are recurves, others straight; some bendy handle bows, others stiff, some glue the siyahs this way, others that way, etc. But there are commonalities, and that's why we can talk about this kind of bow one type of bow. What they have in common, as far as I understand it, is the use of compression wood for the belly (I've heard of spruce, pine, lark, and juniper) and most commonly birch for the back, and siyahs from birch or cherry. The bows in the pictures from museums are from the russian side of things. Bows undisputedly Sámi (northern Scandinavia) are very rare, as far as I know. And I've sought information on this topic as good as I can for the last 5 years. From the reading I've done on the subject, there are about a dozen or so finds in total – and all but one are fragments. And even within this group of bows, there are significant variations in design.
What I find interesting is that even though there are variations in design, the different bow cultures might have a lot in common in the way the made there bows, leading back to the "logic" of how compression wood works. And this "logic" is different from the one bowyers brought up on a strict diet of TBB is used to. :-)
That's my two cents about that anyway. Feel free to disagree! Sorry for the confusion, and the thread drift.