If someone is located in Europe, then he/she might trust in the shafts from Jürgen Arnold at
www.whitewood.de He has got Ash, Birch, Larch, Pine and maybe some other stuff.
I had very tight spine and weight tolerances. This, in combination with good initial straightness and smoothness, has convinced me that I've finally found my source for shafts.
After 20yrs. POC I switched to Birch shafts in general, but I have some Larch also. Especially for my ELB battleshafts. They have a good weight in them and do fly just great.