Help with CA DMV VIN verification form

[Pick121]

OK guys, for my 1963 C50 I am filling out a Calif DMV “Verification of Vehicle” form, it is asking how the VIN is attached. Who can tell me how they are attached on our old trucks, as I can’t tell for sure. The options are:
Not Visible
Rosette Rivets
Round Rivets
Other:______
Adhesive
Not Applicable
Screws
Stamped

Here is a photo of the VIN plate, it really does not have any rivet per se, just a stamped dimple if you will on each side, so does anyone know the correct option for attachment to the door post? I don’t want to make yet another fruitless trip to the DMV office!