Replacing drivers in Sonus Faber speakers..anyone?

There are appliances (i.e.: silicone oil) on spray cans to maintain/freshen up plastic and rubber surfaces in cars, which you could apply on a soft cloth and gently clean the polypropylene cone and rubber surrounds on the GH's, after they've been dusted off. This will also prevent the rubber surrounds from hardening up and keep them supple. Leave the dome tweeters alone, other than some very gentle dusting off with a very soft brush. Once treated (i.e.: the woofer/mids) I wouldn't worry about the age of the drivers. 

Lovely speakers, btw. 

I wouldn’t replace any drivers unless they’re problematic, and even then it’s better to repair than replace, as they’re proprietary to those speakers.

You could rotate the woofers 180° to offset the effects of gravity over the years,  

replace working drivers is a wasted effort. unless they stop working, no need wasting money. you're worrying about nothing @daveyf 

@phusis  in the past, I resorted to using a mild silicone oil on rubber surrounds. I won’t do that again, as I noticed it tends to actually increase the demise of the rubber, due to an increase in the drying out cycle. 
 

@ghdprentice  I believe the GH woofers were sourced from Audiotechnolgie and not SEAS, but they were custom made for SF. The tweeter is made by Dynaudio and was also modded for SF. I’m hoping when the time comes that maybe Fine Sounds, if they are still the SF US rep, will have access to the drivers, but I’m not sure if they do. Which is why I posted my OP.

Here's a revolutionary idea: ask Sonus Faber.