Picked this up at a muddy March flea market for two dollars. It has numbered notches and a rotating top plate, but no obvious way to attach it to anything. What is this thing?

Proper care of a brass seed dial involves gentle cleaning to preserve its patina while removing any dirt or corrosion. A soft cloth and mild cleaner are often sufficient, avoiding abrasive materials that could damage the surface.

To display the dial, consider a stand that allows easy viewing of its features. Shadow boxes or wall mounts can provide attractive options, ensuring the dial is both protected and showcased as a piece of history.