Thanks! Yes this customer wanted a lute based on my zenne oud model, which has a wider body and shorter neck.
The frets are made from string tied around the neck, as frets were made this way on many historical instruments, right up until the baroque period. Many modern instruments still use frets made this way, such as the Turkish saz and lavta.
One of the advantages is that this makes the frets moveable, should the player wish to play non-western or historical scales.