fuel filter mating surface leak potential

This is my first secondary and final fuel filter replacement.
I have 2 L540F Luber-finer filters which appear to be a very common design.
Looking at the mating surfaces where the filter drops into the canister and contacts the cup (#5 in diagram below), it appears the metal holding the cork gasket will make contact rather than the cork itself.
It appears either the metal on the filter compresses down enough where the cork contacts cup #5 or I need an additional gasket between the two.

That's why I'm changing to spin on filters ASAP. I just changed those too myself and observed the same thing. I THINK/ HOPE that under the pressure of the spring when it's all back together the cork actually contracts the cup instead of the metal part, and hopefully the cork will swell some. That's pure speculation on my part however.

I will likely do the spin on filter mod also.
A 2nd issue was the under side of the cup (part #5 in the diagram). The washer (#4) was missing. I have a pack of air conditioner o-rings of many sizes and found one that fit on the shaft and another size that fit around the cup where it contacts the metal on the filter.

You can see the old filter had a very thick seal with no metal on the inner diameter. It appears it would make a better seal with the cup:

I had a similar issue with the washer, except I tore it up but found an o ring at Rural King that seemed to work.
Here is the rather long thread that has some helpful replies.

http://https://www.steelsoldiers.com/showthread.php?181857-Sludge-in-bottom-of-filter-normal

Please put the brass bowel thing the outer way so the edge will cut into the cork making the seal. Using an O ring then O ring on top of last washer then brass bowel thing. So on the shaft down in the canister hole there is / should be a cotter pin. That stops the first washer from falling into the very bottom of the canister. So it starts first washer, then spring, then washer, good size O ring then brass bowel with bowel facing up or cutting edge into the cork.