...we have now found the missing 11mm inserts...
Yay!
I store my spares in their little plastic zip-top bag inside the inner mesh pocket of one of my Ortliebs so I can find them again if needed.
It is compulsory to lose some small but vital part just as you are about to depart on-tour.
Your mum-in-law will now be safe, as she has complied with the Law of Last-Minute-Losties.
Best,
Dan.