30 yr old speakers- time to replace drivers?

I have a pair of Infinity 7 Kappa’s i bought new in 1992 that I power with a Yamaha M70 amp I purchased new  in 1983 when I was 23 years old. I had the amp recapped for $350.00 by a local shop recently, in Dallas. I had  the subs refoamed a damping upgrade added to the spiders and the polydomes rebuilt by Miller Sound in Pennsylvania(they have the parts to fix the polydomes made) for a total cost of speaker repair $405.00. I swear they sound better than new. The kappas are as beautiful as the day I bought them. This system has a very warm sound and is perfect for my family room. I do have a listening room/Man Cave with Zu Omen def supremes powered by a Pass Labs XA 25 amp that is obviously superior by most any measure, but with DAC and streamer added in is an $18,000.00 investment. While I love the Zu ODS/Pass Labs system if I didn't have a spare 20k including cabling laying around I could live with my old system and be happy. I say if you like the sound of your system tune it up and save some cash.

I wouldn't spend money upgrading the drivers and crossovers unless the speakers have a real special place in your heart.....it's just not cost smart in my opinion.

I did that on my original 1980s Infinity RS Kappa 7s, but I've owned them since new and were my first audiophile speakers.....and are very important to me and my journey; won't ever let them go. Plus they now sound amazing

Short answer:

If they’re being used as surrounds, I’d leave them alone and play them until the woofers fall out.

Long(er) answer:

I’ve been doing speaker mods for decades (including owning a speaker patent).

Here’s some thoughts on the subject of "fixing" old vs new:

It’s very unlikely that a "healthy" woofer will degrade much over time. Rubber surrounds have a long life expectancy. We’re pretty proud of our work, but are still surprised (and often stunned) at how much music can come out of vintage drivers when you get things out of the way that make them sound worse. There’s a difference between "fixing" (repair/replace damaged components) and upgrades (improving the sound quality) of a speaker. "Fixing" old speakers is usually very cost effective and a no-brainer.

The following comments refer to upgrades.

We set a budget before we begin upgrades. This budget is 40% of what it would cost to replace the item with a new(er) version of a similar design. If the hot, new version (same brand, or other brand) is, say, $2,000/pr, then I set a ceiling at $800 for modifications. This number is not arrived at scientifically, but is merely a performance vs cost evaluation based on my experience. It represents a number that is less than half the cost of a new replacement.

While it is possible that the modded version of an older model may not exceed the performance of a new model, it is also VERY likely that a modded model will do SOME things better than the new model. I say this with some level of confidence in that a modded speaker will most certainly have better internal cabling, better components in the critical signal path, improved connection/termination methods, more attention to vibration, etc. than the production version of the new model. WIth the new model, you’ll still be "hearing" components that are cost-driven, performance compromises due to strong considerations about production efficiency, and serviceably in the field (without a soldering gun), and just hitting a target price point.

This methodology has produced predictable, consistent, and reliable results over many decades.