to restore or not to restore? Eames shell chair  

Whatever material is used, its gonna come down to matching the color. The paint store people do this all the time when they have to custom match something you bring in. They could probably help.
Only 3 variables in matching a color:
HUE: find location of color (as on a color wheel) .. the red/yellow/blueness ONLY
VALUE: darkness or lightness ONLY (regardless of color or intensity)
INTENSITY: color "purity". aka "chroma" aka "distance from neutral grey" - regardless of darkness or lightness (VALUE) and regardless of HUE.
Objectifying each of the variables separately (as above) helps to zero in on exactly what is different, if the color is not a perfect match. Always expect lots of trial and error to nail it down. It helps to have coloring agents that reflect most of the color wheel, as well as a couple of neutrals. At the very minimum, at least the main 6 color wheel colors, and black and white and a brown.
To me, the size of the bolt holes are so large that patching the hole in a structurally sound way scares me more than trying to match the color.

For the colour/holes, sand and save some of the dusting of the fiberglass. Then mix it with a clear epoxy.

I did some here
http://plastolux.com/eames-upholstered-shell-chair-restore-fiberglass-he...