I have made some nice modified, bend in the handle, plains style bows with a 58" hickory stave. Sinew backed, 5" handle, 1 3/16" wide, (bends but is a little stiff and flat in tiller) 2 1/4" fades into 1 3/4" wide limbs, tapered to 1 5/8" at mide limb for 60# at 28",
tapered from mid limb to 5/8" at the nocks, then retapered the last 8 inches to 3/8" nocks. This is a sweet little sinew backed bow.
The sinew will usually pull the tips into a little shallow recurve. Other than that, I don't recurve this.
Was there any particular reason you wanted it Pyramid? As far as looks go, I like this willow leaf design better. The narrowed bend in the handle design with working fades is a bit tricky to tiller, but it makes tuning the arrows to the bow easier. Leaving the handle a little stiffer, keeps it from overstraining, while giving you the extra 2 inches of draw you needed to get to 28" It will be months before you get rid of all of the moisture the hickory picks up. In Cal. I would let it cure 3 weeks min. before tillering it and working it. 1 month is better.
Dan