Check out this on Youtube https://www.youtube.com/watch?v=WXJYWDQBjkI
its a video from Creative Paradise & really the definitive on making dragonfly's. Their LF111 mold is pretty much the standard - bigger than it looks BTW but then you may already be using it. I use the wire Nichrome wire from Fusion Headquarters. Works good. Tried all sorts but most discolor but if thats not a problem any wire will do. I have embedded a SS set screw that I then use a threaded coupler to join to a threaded rod. Frankly you can embed anything that will stand the temperature into the frit.