I fix them quite often. The guy sends me the bow, I get measurments of width and thickness, Make a form by clamping it down and tracing the shape of the back, remove the limbs and grind all of it off the riser down to bare wood, glue up new limbs on the form I built, so on and so forth.
The I write what sort of bow on the form and save it for the next one I have to do. The form I use the most if for Damon Howett hunters.