I do have a solution for you. I was looking at the pictures and recognized the tweeter as the old SEAS H-087 35 mm tweeter. This was used by AR and Dynaco and others. The old tweeters are failing. However SEAS have introduced a
replacement I find, because of demand. Since this is specialist the price is a little high.
You will need to replace both, so it will set you back $504.80 plus shipping.
For those speakers, I would say it was worth it.
The sensitivity is 1 db higher then the original, but that is not enough to warrant messing with the crossover.