Replacement woofer for Green Mouintain Audio Europa

It's not available according to the link.

The 6 inch woofer is an Aura NS6-255-4A.

You might look into a reconing service like Midwest speaker

Quite often the parts are available even if the manufacturer has gone out of business.

I will give Midwest Speaker a shout. Thanks

Sorry didn’t see the unavailable tab there, but also they’ve posted all necessary parameters to match with different speaker of a same fitting/size. Replacing paper cone won't help broken voice coil btw.

i may be wrong but believe Roy used the 4 ohm version of that woofer not the 8 ohm listed on that website.  I actually have a few spare woofers, have to check but I recall Roy had sent me two extra woofers about 10 years ago.  I still have the Callistos so could probably part with one of the woofers.  He also would make a mark on the back of the woofer drivers which would indicate how he matched them either a slash mark on a circle mark I believe.  You can send me a private message and we can discuss and in the meantime I'll check to try and find the spares I know I have them.