I am looking for gold filled, or non-tarnish brass - lobster, or trigger clasps, but it needs to be large enough to work with a 2.5MM bail, so far I've found that a clasp that is 12mm across and up to 19mm high works if the trigger doesn't block the bail.
I've found workable clasps in sterling but not in gold filled (gold plate will not work)
workable solutions in silver
https://***/cart/pc/viewPrd.asp?idcategory=0&idproduct=12740
or
***/ss-cl42.html