Hi, Floxxx.
I'd check Etsy if you haven't already: http://www.etsy.com/search?q=padlock...ery&ship_to=US. Some of those are sterling and some are crafted by artisans who might be able to help you if you contacted them directly.
Likewise, I'd check eBay's Adults Only category. Start at http://www.ebay.com/sch/allcategories/all-categories, go down to the very bottom where they have the category "Everything Else" and sub-category "Adults Only" and then sign in. There was a slug of padlocks, including silver, there.
For what it's worth,
S.