<<Is it possible the "reversed spool valve" was the design intention of
the manufacturer?>>
We do in fact use the pump in a non-standard configuration with the work
being done during cylinder retraction instead of extension.  Therefore,
when viewing the generic pump schematic from Oildyne, high and low side
are backwards.  
My original pump was assembled correctly.  Some time after '95 the build
instructions from Lancair got mixed up and every pump was being
assembled with a reversed spool valve.  Every pump I have worked on
since then was backwards including the spare I bought for a hydraulics
test bench.  I'm sure there are quite a few out there still needing to
be fixed.
Chris Zavatson
N91CZ
360 std