Let's make sure we are all talking about the same parts here. Part 13 is a metal washer that sits up into the bottom of the filter and is often discarded because it sort of "sticks" to the filter and so you remove the filter and throw it away not realizing the washer is stuck on the bottom. The rubber grommet i THINK sits in the center of that washer hole, not quite sure what purpose is serves, and I agree it's odd that it seems we can see it on the top of your spring with the bolt coming up through it, suggesting that maybe it separated from part 13 the metal washer. I have both parts 13 and 14 (metal washer and grommet), let me know which of the two you need. Mine is also grayish-white rather than the black shown in the previous picture posted. I'll dig these out and post photos here.
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