Originally Posted by HillRider

A magnet will tell you immediately. Galvanized spokes have carbon steel under the coating. Stainless steel spokes are non-magnetic 300-series stainless. Some stainless steel spokes may show very week magnetic attraction but the difference between them and galvanized (or cadmium plated) spokes will be dramatic.

I agree, those are awfully good rims and highly unlikely to have been built up with galvanized spokes.