Plug,
They're not a jig hook. Offset stainless beak type. We use them on rigged eelbobs that we leave in brine solution.
We did at one time pour jig heads with them - we had to insert some brass sinker eyes into the hook eye and then make them fit the jig mold. Pain in the ass - but those jigs didn't straighten. Might be worth a shot if you're fishing jigs.

DZ

I've seen the sinker eye thing done. I've also considered bobs. I like the idea of a swinging hook. But down here in this fast moving water just a straight jig has always been very effective and is about all we've ever used. That and squids. I'll have to incorporate some more Yankee methods.