Hi, Opened my packs of spokes I bought from DSS in 2009 as member Kettle738 advised me they may not have the correct gold passivated zinc plated nipples. He was correct they were found to be silver BZP.
Anyway experimented in the 'lab' late one night (my utility room). Washed one in isopropanol to de-grease, cleaned with tissue, rinsed in de-ionised water then put them into the gold passivate solution from Gateros ( a UK company but Eastwood/Caswell probably sell the same stuff), rinse again then looking good. I didn't believe you could re-passivate gold (Chromate) after initial plating and possibly blue passivated treated but they look spot on to me.
http://gaterosplating.co.uk/Replacement-Items.phpAgreed though, If you can re-plate the originals that's probably the best way forward. I find that if a wheel has a decent rim, the spokes and nipples are usually in a condition to have re-plated. Bake in an oven afterwards though to de-stress, as also advised by Steve.
Cheers .. AshD