3D models are symmetrical and drawn in high-quality, so you just need to scale it to the desired dimension in your 3D project. You can use them as a 3D design elements, or it can be turned into a bas-reliefs in wood, stone or some other material.
On our website there is a whole collection of ornamental fleur-de-lis 2D designs with which you can make fleur-de-lis 3D models.