Nope, you can't get them anymore. They were a Tokuno Minor Artifact, while the NPC only gives you 1 Greater Artifact in exchange for 10 Tokuno Minor Artifacts. The best Flutes of Renewal, are the Arachnid and Elemental Slayer ones, since those properties aren't on Gwenno's Harp or Iolo's Lute (which still spawn).
I used to have so much fun stealthing around Beetlescape on my Stealth/Fencer, and popping out to 1 shot Evil Mage Lords with my Night's Kiss dagger and immediately disappearing due to Shadow Strike. Was a good way to get Tokuno Marties, since it was based on the fame of the mob, and Evil Mage Lords had Lvl 5 Fame. The only thing that sucked, was getting revealed and DPed/Bleeded by a Rune Beetle before i could Shadow Strike it (the DP/Bleed would then repeatedly reveal me).