On our last boat I removed all the ports and had them anodized.
The boat was a pilot house with 15 large ports.
The ports had to be completely disassembled and most of the old caulking removed.
They had some corrosion, but no deep pits.

The anodizing shop "belted" them to a brushed finish, cleaned them in an acid bath and clear anodized them for $400Cdn.
They looked like new, and lasted well.

On the same boat I had the steering pedestal Powder-Coated. It had some deep pitting of the aluminum. Sandblasted, primed and Powder-Coated was around $175. It lasted about a year before it started to bubble up and fall off, looked worse than when I started.

Cheers,
JM.