Sorry I overlooked this in my reply: I too was also faced with the question of whether to attack the problem from directly above which seems the obvious and disregarded the other steps.
I think you are on the right track in sourcing the o-rings from the experts such as a Bosch or injector service
centre as sometimes OEM parts
such as these may not be quite up to scratch. Or even may not have been genuine OEM parts
that were supplied since they failed so quickly. The previous engine was 28 years old with no leaks
but worn out. Like your o-rings mine had cracks in them too. I will take the samples to my local injector service and see what they say. I am inclined to replace what appear to be the sealing washers located directly under the delivery
valve body as they seem to me to be the parts that are doing the work of sealing and to me the o-rings are more of a secondary function. In my pump those very washers seem to be made from soft iron. Other pumps have what appear to be copper washers. My original though was that the sealing is done by the metal washer and the o-ring simply sealed the thread to prevent corrosion
caused by seawater environment
. We will see how we go.
Our cruising grounds are between Pt Davey Tasmania and Cairns.
But next we are hoping to cruise
the Bass Strait Islands in summer and then head
north for winter. There seems to be a restless "itch" to get away.
Thanks for your info.