Green Mountain Audio

I would also agree to refoam and not try and replace the drivers.  I know Roy would also for some drivers write - , 0 , or + on the back of the drivers as he would then match the drivers and only include the same matched drivers that he individually tested.  So for instance both tweeters would have the marking - on them not - and then +.

I've owned the Europas, Callistos, Eos HX and C1.5 and they were all excellent speakers.  I still have the Callistos and spare woofers for them.  I've since upgraded to full range speakers but the midrange, detail, soundstaging and realism of the Green Mountains was first rate.  I also enjoyed speaking with Roy on many occasions although I really didn't understand all the physics.  I always felt like I just had a one hour physics class when the call ended.  He was such a great, knowledgeable guy.  I was in line to get the EOS ribbon tweeter model but unfortunately that never happened.

I never met him but have never seen anyone post that he was anything but a true genius and a really nice guy. I saw these in a local ad and couldn’t believe a pair would be tucked away in the middle of nowhere. They were not in the hands of an audiophile. Covered in dog hair and dust, and by nature not very attractive, they were a sorry lot. They will come back to life and stay in the family collection. I don’t like to see vintage high end go to the trash or destroyed. 

If you picked up the pair in south NJ, I’d like to hear how they turn out after repairing.

miller sound is your best option for quickly getting them up and running at/near close to original spec.

regarding resurfacing the exterior, I would suggest a slightly left field approach: cover them in leather.

you can find dark brown leather that looks rich, like wood and will be forgiving to apply with 3m interior trim spray adhesive.

I would also suggest hitting the interior wiring connections and crossover circuits with deoxit to freshen up the connections 

Appreciate the recommendations. leather may be a good choice but I am familiar with veneering techniques and a Rosewood or straight grained teak might be just the ticket for these. I also thought about veneer that has a pronounced heartwood color that could be centered down the front bevels. We shall see. The foam surrounds are a full 203CM/8" so most aftermarkets wont work. Ordered originals which take a bit to receive.

I had a pair of the first run Diamantés with solid black bases and the dark green swirled uppers.  I liked the appearance of them.  I toured the factory in Colorado Springs and spoke with Roy prior to purchasing them.  The speakers have a  live sound and excellent reproduction of dynamics.  They were definitely not a warm sounding speaker in my setup.  More of a sit up and listen presentation than a sit back and relax.  
I used OCOS speaker cables with the snap connector ends which greatly simplified installing the uppers onto the bases.  Routing speaker cables through the bases and trying to pull back the excess cable whilst placing the uppers on the bases was a PIA for one person.

Amplification at the time was a Classe DR5 preamp and a pair of Classe DR8 amplifiers.

You might want to look to see if yours have some of the updates.  The first one, and one that made the most significant improvement was the addition of C channel aluminum braces which were bonded to the lower sides of the cabinet in the woofer section.  As I recall the braces were composed of two per side, four for each speaker and bonded with construction adhesive.  The instructions also stated to remove approximately 18 inches of the wool from the transmission line. I did the install myself.  Later on there was an upgraded crossover, Series 3? which mellowed the speaker.  I didn’t like the crossover upgrade and eventually sold the speakers.  I don’t recall how one would identify which crossover is which.

Good luck on your project.