The Weber site is not very good for parts. Have you tried ereplacementparts.com? Either that or call Weber, they can look things up that are not on the site.
If you do find that they are unavailable, is it something that could be easily fabricated?
Dave,
try this site. You should be able to get a good parts diagram and it will should show if the parts can be bought separately
http://www.ereplacementparts.com/we...medium=PPC&utm_campaign=weber+-+search+-+mike
Greg and Rick,
Thanks for the links to ereplacementparts. I had checked there and at appliancefactoryparts, and at grillparts.com (side note: Learned about these places a couple of years ago from lurking and reading here) At Ereplace and appliance, again, the part was just listed as a kit. At least for the couple of different schematics that I looked at. It's entirely possible that it might be listed separately on a schematic for some other grill, but I was hoping to avoid having to go through every single schematic one by one trying to find it.
Grillparts also has just the kit, but in the description they call the metal thing a "spark box". That was of little help trying to locate the individual piece.
With some help from my ADD, somehow I stumbled on a site that labeled the piece as a "Weber BBQ Gas Grill Steel Collector Box." Unfortunately, all I have found when searching for this always includes the electrode as well and the price starts at about $10 including shipping. Would be easier and about the same cost to just go to Home Depot and buy 4 single electrode replacement kits and just use the boxes from them. Then again, at $40 for the 4 I need, just replacing the whole ignition system wouldn't be too much more.
I was seriously hoping that someone sold just the box alone for $1-$3 and I could replace the 4 for under $20. Guess that isn't happening.
Turns out that refurbing a Summit Gold D is a heck of a lot more expensive and involved that doing a Genesis B or C

Heck, new flavorizers appear to run over $150 alone.