You can get all kinds of small fittings, latches, etc. in bronze, chrome, black nylon... at one of the Marine Hardware stores. There are a few on Lake Union (up by U of W) and there is Seattle Marine - they are online at http://www.seamar.com/ and have a store (I think it's on the south shore of the Ship Canal).

You might also check Mariner Kayaks - they are on the West side of Lake Union and at http://www.marinerkayaks.com/