Anyone repair/replace Snap-Jet ignitor on Summit grill?

My neighbor has a Summit S-420 with Snap-Jet ignition system. He's got one burner that will light manually with a match, but won't light when the knob is turned.

I thought it would be simple enough to lookup and order the necessary replacement part, but after spending about a half hour on it yesterday I couldn't find anything. And on Weber.com it says to call their support number for all Summit ignition parts.

Anyone have experience with this? Assuming you can get a replacement part from Weber, is it an easy fix?

So basically one of two things usually happens. Spider nests and rust clog the tube that inject gas, so you can remove the one Phillips head screw on top to pull it and blow it out with compressed air or use a thin stiff wire to probe it and remove the contamination or otherwise, the electrode falls off because of rust on the tiny claws that hold in. The individual tubes aren't sold separately which annoys me as the majority of times I swap valves and manifolds are due to a part that should be under 10 bucks failing. I'm not even quite sure if individual valves are sold as we always pull them from manifolds we stock but I have seen a few websites selling them which leads me to believe they are, I just don't have the part number. All summits from the 400/600 series use the same valves for the main burners, I've seen different stamping on some of the replacements so I'm thinking there may have been minor revisions or a change in OEMS at some point in time. Also, ducane used a similar setup but on a 30 degree angle on their stainless home depot grills post weber buyout so I believe that these were the precursor to the summit setup. If you ever see one of those grills junked, and you often do, grab the valves to snag the parts from and make sure to pull the silicone boot and grip the terminal as far back as possible as the wires love to pull out