It is actually HHB heartwood Pat. You need a tree at least 6" in diameter for it to start having any substantial amount of heartwood. HHB heartwood is very slick and scrapes like butter. The backing is a quarter sawn strip I cut from a stave.
I started on one about 7 years ago Adam but never finished it, it's still sitting on a rack. I was trying to make it without splicing in the recurves, tough to do. One of these days I'll get back to it