RE: What is my responsibility?
How can you be so sure it is the engine you sold and not another one he got somewhere else?
I understand and applaud your concern.
However, relying on pictures may be putting you on a slippery slope.
Be very careful how you word your comments.
Something to the effect of "If this is the same engine I sold to someone then the properties are ......"
Your ethics are to be commended.
Good Luck,
KW_Counter