Diameter Of Detente Ball - T120 Passenger Footpegs

So... while installing pannier racks on my 2017 T120, I managed to lose BOTH of the tiny detente balls that are part of the passenger footpeg mounts. (Sort of a ridiculous design, given how easy these are to lose.) They seem to be the same part used in a wide range of Triumph passenger footpegs. I can order them online but shipping seems to be like 6x the price of the actual detente balls, so I'd like to look for stainless steel balls at Home Depot for a fraction of the cost.

Two questions:

1. Does anyone know, or know how to find, the diameter/size of these detente balls? (OEM part # T2081675)

2. Does anyone have any guidance or tips on re-installing the passenger footpegs without losing these tiny little buggers? I'm sure I'm not the only person to lose these.

 

Ah, thank you! You're a better parts sleuth than I.