Dura Ace outer chain guide plate replacement?
Does anyone know if you can replace the outer chain guide plate on a DA FD-7900/7970?
I discovered a small chip in the nickel plating on the chain guide's outer plate (near the front...odd place) and it's annoying me more than anything. Looking at the techdocs on Shimano's site, there is no part number for just the outer part of the chain guide, but it does list a "chain guide fixing screw", which suggests the outer plate might come off. Looking at the cage itself, it appears that the inner and outer plates are separate pieces but it's possible that they aren't designed to be field serviceable and won't easily come apart.
I searched but couldn't find any info on this topic. I called the Trek dealer to see what they thought and the tech said that Shimano probably wouldn't warranty it. I don't mind buying a new outer plate, if possible, but I have a sinking feeling that, due to the lack of a part number, this isn't possible. I'll most likely have to live with it but was wondering if someone here might know a bit more.