This is a great resource for making your own rosettes
 
https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwjCi6mJmvvrAhWHiFwKHT1EDhoQFjABegQIAxAB&url=http%3A%2F%2Flutherie-guitare.org%2Fwordpress%2Fwp-content%2Fuploads%2F2015%2F05%2Fguitarmaking_guide.pdf&usg=AOvVaw3KsDkSoEyuddSH7jb9iXGU