I built 2 Osage bows like that. One I added bamboo and another I used a hickory strip. BUILT THE BOW INTO BOW FORM. TO FLOOR TILLER SANDED THE BOWS BACK DOWN FLAT.
The bamboo I also had to sand flat to match to bows back. The hickory strip was much easy er after I cut got it out.
Glue, raped with ace bandage let them dry in the sun for a few days. If possable.
Then finished the bows form,tiller,finish. Both bows were fine and good cast ,sweet shooters.
These bows were in my younger years when I did and try ed everything possable. I quit backing bows years ago.
The reason I did this was the Osage rings were thin slices way to thin to follow. I really didn't have anything else to back those bows with at the time. And for these backings to work you have to have a flat surfaces to glue together.
The bamboo bow was sweet 60" 61#@26" I used it 2 buck seasons 2 does and a 9 point. Plus I shot a 10 point the second fall,that another guy arrowed him the next morning. He scored 136 2/8"s. And one spring gobbler season I missed 2 with it.