Two different maintenance companies. One for the first two fixes, one for all the rest.
The pumps have come from two different suppliers - the same results both times!
It's a non-turbo Arrow. The pump is the rotary type (not the "ticker" type that carburetted Cherokees have).
The contamination claim was after last week's failure. We've never got any water out of the fuel drains; I suspect it was just an excuse to avoid the supplier having to replace it under warranty.
We were TOLD that four of the new pumps were brand new - no proof, of course.
Keef