String identification

flaco

A while back I bought a guitar from a shop, and I'm trying to figure out what strings were on it. They don't look like the traditional silver-plated copper, they look more like nickle strings. They were loop end, they feel about like 11 gauge, and they don't have any colored silk wrapping on the loop end. Any idea what these might be? They had a bit of a warm tone and they lasted forever, so I'd like to buy some more. It seems like the loop end should narrow things down, because a lot of the less mainstream strings only come in ball end.