Lead per mile is actually lower on your longer run.
However, since this thing is changing its own oil as you drive, that may not mean anything, although iron wear is linear between the two samples, and quite low.
I agree that it would be worth getting a Dyson consult.
Could this just be a prolonged streak from a largish particle, or a collection of them, passing through the bearing(s)?
Remember, lead per mile is actually lower in your second sample, so could this excess wear be gradually fading?
Terry would have a pretty good idea of what's going on.