I undertstand that artic birch is something for the american taste. it seems they liked higly figured wood very much and see also their love for maple gun stocks.
http://www.gunstockwood.com/
arctic birch gun stock will always sell in the united states!

still waiting for your report showing the mannerheim collection in detail

"Hunting was one of Mannerheim’s outdoor activities until the time of war. The following weapons are in his collection:

– A Berdan rifle, m/1870, 10,67 mm from the year 1882 and two from the year 1887,

– An infantry rifle, m/1896, 6,50 mm,

– A Steyr infantry rifle, m/95,8 mm,

– Two shotguns (William Powell & Son)

– A Mauser hunting rifle (Obendorf)

– A Mauser hunting rifle (Tiroler Waffenfabrik)

– A Mauser hunting rifle, .350 Magnum Rigby, half-stock (since 1936)

– A Mauser hunting rifle, Purdey & Sons

– A moose rifle (Sako 1943) and

– A Caucasian hunting rifle"

hunting red deer as a guest of Hermann Göring in east prussia 1935