If you are going to use another tweeter you will have to modify the crossover, which is not easy, unless the characteristics of the new tweeter are the same as the old one.
Alternative tweeter
I would like to hear from any owner/user having replaced their VMPS 626Rs 'FST or Ribbon' tweeter with the Aurum Cantus " G2Si " ribbon tweeter, or any other possible alternative that garnered good results. I am a novice in the audio field looking at all feasible replacement for a pair of non-working tweeters. Any and all input is kindly appreciated, thank you.