Can you get any worse photos? 😆 edit they look better now 😀
Looks like you have the order pretty much right but yes the large part at the end is odd and the part before it looks like the crown race.
Which one of the last 2 parts fit in the bottom bearing the best?
Could it be a 2 part crown race with one being for 1/8th and the other put on top of the 1/8th one or just fitted to a tapered fork?
Or if both the same diameter maybe the thick one is just to give extra height in case your fork crown knobs hit the frame – as can happen on some forks with integrated or semi integrated headsets.
In which case you would use one or the other. Like the CK or Hope +3 or +5 crown races.