I found a current supplier of both the fuel petcock and grommet used for the fuel tank. Exact match of the ones I found on all of my tanks. This does not mean the only one they used, but was for the tanks I have seen. There was an older link to Wicks Aircraft, but they told me they no longer carry it. There is also a pic of the current part numbers since links don't always last.
Here are a few pics:
http://www.flambeaufluids.com/
866-836-0198