broken 7400 shifters

so i got those 7400 shifters for a song, owing to the fact that they didn't change down reliably.
half a can of wd40 and they feel much nicer.
However... one of the white washers on the





cable hook unit (part number Y-6BD98110)
is missing. i have 2 new units on the way.
incidentally they use that part in their 6400/7400/6500/7700/7800 dual control levers as far as i can tell.