Problem #1, Mr. Mattingly -- If the process you described is truly the origin of the image on the Shroud, then why aren't there more of them? Especially when you consider how relatively common a crucifixion was at the time. Not a problem: crucifixion was reserved for criminals, who were generally not given proper funerals with shrouds. IIRC, their bodies were generally dumped into graves outside the city walls.
Jesus was given a proper burial, in a tomb and linen provided by Joseph of Arimathea. (See Mark 15:42-47.)
Do you mean to tell me that in all of the centuries of the Roman empire, there was only one case of a crucified "criminal" who was given a proper burial?