You have to say... how much bow.
For 50# @ 28", no worries generally but details matter. I pic of all these check and craft features would help.
1 1/2" is a good width for osage, but when in doubt run the full width to mid limb, and tiller accordingly. I personally don't find the "pyramid" shape all that compelling, other than for style reasons. I tend to extend the fades more gradually and run full width a few inches. Actually more like a parabolic shape. With abrupt transition, getting the inner limb to work up to the handle, which I find desirable, is not as easily accomplished. imho