The Duelunds speaker crossover inductors 1.5mH pair (for my Altec 604E n1500 crossover) will cost $750 WAX and $700 Cust. Not cheap. The Jantzen Wax Coil that I use now cost me just $150.
I use a Duelund silver bypass in the same crossover to bypass the 14uF capacitor. But I think Duelund silver has some little kind of brightness.
I like the Soviet silver mica SGM-3. They are really great.