I usually like what Faber-Castell does with wood.
Everything seems pen
ultimate to Hakase, though. I haven't seen many good photos of their pens, but the catalogue looks amazing and recently a member of FPN posted theirs. The ordering process is as close to bespoke as pens get, with writing angle considered and such.
Here's the mentioned member's pen, his photo. The threads are wood! Made from cocobolo.