Since most non tarnish silvers have reduced copper content, and have
other metals added instead, non tarnish sterling is softer than the
traditional mix. Most fill well, and even fabricate well. There are
many "flavors" available these days. Most major alloy makers offer
this sterling alternative. PMWest, United PMR, ABI, to name a few.
You may want to find a non tarnishing solder to match if assembling
parts.... Some are appearing on the market.