Rudolph,
I would feel compelled to write something similar if I were faced with your situation. I wouldn't bring up the FAA. But I would certainly invite the owner to meet with your mechanic and discuss the findings as you suggested. Like others here mentioned, I'm sure the owner would be defensive. But I hope any of us who are not mechanics would feel appreciative of professional input as to the state of our aircraft. I have to put my children in my airplane and feel with relative certainty that they will be safe (I don't ignore the natural risks in life - but I don't keep them in padded rooms either). If the owner felt the aircraft was safe, then who knows who he is putting in this plane. Hopefully, even if he is upset, he will seek perhaps a third mechanic's veiwpoint.
