I think I would find an experienced framebuilder that's willing to TIG it for you. I have no idea who that would be. TIG has the advantage that the heat is more localized, so it's less likely to mess up the paint/chrome.

I'm with Andy on silver. I would only do it if it was the zombie apocalypse and I had to have a bike to escape with my life. Replacing the steerer seems like a better idea.