tweeters & mids - what is their life span?

I have a pair of Sony SS-M9 as my main speakers in a combined 2-channel & HT set up. My center channel is a Gallo Reference AV.

My pre-amp is an Arcam AV8, which has both an analog 2-channel pre-amp, and analog & digital multi-channel processing.

Lately I’ve been listening to a lot of CD’s and LP’s, which I normally listen to in stereo, but I have gotten into the habit of using the AV8 to send an additional combined signal to the center channel. The Gallo seems to add an extra richness to the middle, especially with jazz and female vocals.

A couple thoughts occurred to me.

1) Maybe the tweeters and mids on the SS-M9 need to be upgraded? These were made circa 1995, so they are 12+ years old. Anyone know what the life expectancy is of these components? I am the 3rd owner of these babies, and the previous owner did not take the best of care of them.

2) If I do upgrade them, does it make any sense to try and match them sonically to the Gallo? Or am I just chasing puppy tails?