The deal is: English sycamore is very similar to America soft maple. Sycamore from Scotland and Yorkshire is more similar to the harder American maples.
Thus, maple, and particularly rock or sugar maple, is an excellent wood for knitting sheaths.
Two Yorkshire style knitting sheaths made from rock maple.
Every time I use "goose wing" knitting sheaths, I am amazed at how well they work for gloves, hats, and other small knitting when tucked into apron strings I love them.
My thanks to Chris at Robert Sorby.