There was another thread on this subject in Rumours and News. On this subject, we at Brits used to get filter kits, but now we have to order each individual item which can be very time consuming. I much prefer to have everything on one order.
Back to your story Leatherman, was it not possible to stores return the unused items? Surely each individual 'O' ring and filter assembly has it's own stores batch number? Just a thought.