The Gran Trajet crown is designed around a 48mm tire. These crowns have 62 mm of clearance between the blades. These have a 28.6mm "crown race" and 25.4mm internal sleeve.
The curve of the crown was designed to accommodate a Honjo fender.
If you're not a frame builder, they look cool sitting on a shelf, do a good job holding down papers, or would make for a good piece of an art project.
You will need to use Kaisei Toei special blades.