Broken/missing parts Eames 670  

No, I would not trust the repair.
ES670 parts do come up occasionally on eBay or you could try other sources like Hume Modern in LA. Alfie can advise you on your back panel, too, but be prepared for sticker shock.

I agree. Looking at the crack...
I agree. Looking at the crack makes me cringe already, let alone sitting in the chair. To get some peace of mind, I suggest you get some professional opinion on it. I hope you didn't pay too much for the set.

Thanks for the feedback
I only paid 200$ i have been in contact with several professionals and I am waiting to hear back from them. Still looking for a base!!! 😉

If repair estimates are too...
If repair estimates are too high or you can't find a base, a good fallback option might be to turn your chair into a parts piece for others. Can you post some overview shots of it?
With miscellaneous pieces and cushions in decent shape, you should be able to recoup the $200 pretty quickly.

At one point, I purchased a 6...
At one point, I purchased a 670/671 in need of restoration. However, it turned out to be too much work and money involved. It had 2 irreparable cushions and a seat pan with 4 drilled holes. I paid $800 for the set. I ended up selling everything in parts and came out $1300 ahead. Of course that depends on your location. Craigslist and eBay have been my main platform.
In fact, selling the parts may make better sense for you so you can put the money towards getting a chair set in better shape because after all, a 670 with a cracked panel is a 670 with a cracked panel. Good luck.

I am waiting to hear back on...
I am waiting to hear back on repair estimates for the ears. All of the cushions are in good shape. No tears, just missing buttons on the base cushion and slight cracking on 1 arm rest. The other shells are in excellent shape. Worst case I will purchase a repro shell from modern conscience ($600). Has anyone had experience with their craftsmanship? A new 5 star base from HM is around $450. I still think $1275 is a good investment for a future heirloom. Thanks again for your thoughts. Again, Anyone have a base I can purchase from them???
-Ben

My dear Ben,
If you should choose to keep the chair, consider using authentic Herman Miller replacement parts. Nobody wants a Frankenstein'd Eames chair. Nobody.
Best,
Aunt Mark

Thanks mark. I agree. I...
Thanks mark. I agree. I would like to be able to pass the chair down as an heirloom. I will do my best to use authentic parts but I was just wondering if anyone had any experience with the repro shells. cheers.
-Ben

I would just sell it as is on Ebay
and be done with it. Here is a link of one that sold that looks pretty F'd up. Use the money you make towards a "nicer" vintage one. Liveauctioneers may be a good way to go to find one as it seems like there is a better chance of getting one cheaper on there than through Ebay. Usually have to arrange for a private shipper though which may be a pain.
http://www.ebay.com/itm/Herman-Miller-Eames-670-Lounge-Chair-CUSHIONS-RE...

Based on the pictures they...
Based on the pictures they have on their website, I doubt that shell will come anything close to matching your rosewood shell. First of all, it'll not be rosewood because it's no longer available. Second, I don't think it'll be possible for them to fabricate something that can match the grain of the rest of the chair. I personally wouldn't take that chance.

Here you go
A shell and a base. This is not my advertisement.
http://newyork.craigslist.org/mnh/emd/4197146867.html

Thanks! I emailed the...
Thanks! I emailed the seller. I have several friends in the city that could pick the chair up for me and ship it down. Ideally I would like to repair the chair I found and purchase a new base from HM. That would give me a complete chair! Because I plan on using it daily scratches/cracks in leather/patina to wood don't bother me. I just want a functional chair that I can improve as I get older. Thanks for all of your help. Still waiting on someone to get into the christmas spirit and sell me a base! 😉
-Ben

Spoke with Alfie today on...
Spoke with ALFIE (whoops for earlier mistake) today on the phone and I think we may have a solution!

Artie? And what's the...
Artie? And what's the solution?