Neither the bucket or the trim ring have a tab on the top, just a screw hole in the ring that lines up with a threaded hole at the bottom.
I did some more checking on the vendor websites and they list a sealing gasket that apparently is to seal the bucket with several wire formed pieces (sold seperately) that retain the seal, one of which may include a tab/feature for the top of the ring.
I looked at my original buckets and trim rings (poor condition) but they also do not seem to have a tab although I could swear I saw a tab on something previously. None of these were together when I got the truck but if it was like other parts they probably justed added sheet metal screws to hold the ring in place.
