GW's "The Lost Gem" adventure is where Stonebender was introduced. Unfortunately, the adventurers were en route to Stonebender's shop when the adventure fizzled to a halt, so we never even got to meet the dwarven blacksmith.
For enhancement bonus +2, it takes CL 10th. Since LEW is supposed to be PC centric, I'm reluctant to suggest that Stonebender should be L10. But Rinaldo just gained his 9th level, and in Fallon we have two L15'ers and a L18'er (Mithreander), so I think a L10 crafter is reasonable. Ideally, PCs will buy from other PCs, but that's just not plausible right now.
At the very least, I want Stonebender to be L8, because that means he's powerful enough to make Rasereit's +1 Bashing shield. =P
ADDENDUM: Perhaps, once B4cchus' Master Crafter becomes finalized, we could have some NPCs take levels in it.