That series of Paradigm speakers used the standard Vifa 1" tweeter, d2(X) series, I believe. This makes it fairly easy to get them fixed up. The problems now, supposedly, begin when you have a 0.75" tweeter from that time period on any API or PSB, and Paradigm speaker,as the 3/4" domes from then tend not to be all that replaceable now, IIRC.
Just found some images of the 9SE Mk II, it could be a seas tweeter. These tweeters (Vifa and Seas tweeters) where used almost exclusively by the stated manufacturers (Mirage, Energy, Paradigm, PSB) for a solid 15-20 years. Paradigm for example, started using just some of the components from Seas and/or Vifa, and the rest was custom. I think they still use the domes, maybe..but build their own magnet structures.