I don’t know how to word this so bare with me
1. How big or thick/ long does a branch of a tree need to be to make a knife handle?
2 . How long does the wood need to be cured?
3. Can this be done by a normal knife maker?
Long story but one of these trees overlooks a grave that ended from a really bad story. I’m not sure of the tree type
Also adding to what Jason said, before using the wood for a knife scale it has to be stabilized or longevity, or else it will crack and spilt. It's better before stabilizing the wood to get the moisture content as low as possible under 5% or better. I have a moisture meter before stabilizing my dried wood I put them in an oven of 200 degrees for at least 24 hours.
Not sure what a normal knife maker is; I somethings wonder if I'm normal making knives for a living. lol.