Cheers all, these are great options. I’ll shoot a message to BTN or Yamaha and see if there’s anything they can do. I‘d imagine if the Hipshot does indeed fit, there should be more models that will...
I agree that the tuners feel a bit flimsy, but they work fine for me. One of the, err, ears had come loose from the peg, but that was easily sorted with a drop of loctite.