I recently went through this with the hatch lock on my subaru salted road beater. The lock is constructed just as you describe with the exception that it has eight leaves and I didn't see where anything was numbered.
At first my key wouldn't go in the lock but it was because the leaves were jammed in place with corrosion, etc. PbBlaster was recommended in some of my searches here for cleaning aluminum and so I gave it a try on cleaning the gunk out of my lock. It seemed to work pretty well.
I did as you mentioned and left out one leaf that seemed problematic.
Sorry if this is not what you wanted to hear. I reserve the right to be wrong, others take the liberty. My posts are not intended to be complete, just enough to help you find your own answers. Don't let the Relevance Paradox get you.