Ok, let me chime in here, first off, tungsten is about as tough a metal as you can find... you will find it is used on missle nose cones... Most tungsten weights are 'machined" not molded... Nobody is going to be molding tungsten in there garage... unless your garage is the lockheed skunk works...
my guess is the tungsten jigs and spinnerbaits are a powder epoxy mix... that would make it a really heavy plastic with a tungsten suspension... easy to figure out, grab your tungsten jig with pliers and squeeze, you do any damage then you got a mix... I find it all but impossible to mold a pure tungsten jighead... you would black out your whole town before you got the right tempurature... not only would the hooks be melted but the mold and garage too...
This opens some doors though... Tungsten powder mixed with plastic in molds...
As far as lead bans go, a jighead is still good anywhere, they just ban plain sinkers...