It doesn't sound like a tweeter problem if you get no reading from the crossovers. Being that it's both channels it sounds like they are shot, but not if they are not getting a signal. Meniscus audio used to rewire coils, you can contact them and see if they can put you in touch with the guy who did it for them. I had a Focal driver that was out of production and they were the only place I could find in the US that could fix them, so if he's still kicking, that would be my first choice. Good luck!
Lou