Dart Steering Coupler Issue

Seems about once per week during past 2 years ( I'm 59 ).
I'll see a member needing some simple little easy ship part and I think , "Yeah I have that". On second thought, I better go look. Well shoot, cant find it, must have let it go already.
Most recent was chrome seat adjust knobs. I found 1 spare black on the shelves.
Good hunting