If memory serve me right wasn't Jesus pretty much beaten to a pulp by the Romans before being crucified? How can Jesus be a sacrifice in such a condition in light of Deuteronomy 17.1:
You shall not sacrifice to the Lord your God an ox or a sheep that has any defect of a serious kind, for that is abhorrent to the Lord your God.
I think Watchtower's response to that would be something like:
Evidently, Jesus' sacrifice began, in a sense, from the start of his mistreatment after his arrest. Jesus sacrifice was not limited to his death on the stake but includes his suffering leading up to his death. At the start of his suffering - the start of his sacrifice - he was physically sound in every respect. Thus any disfiguring wound Jesus had before his actual execution do not disqualify his body from being a suitable offering to Jehovah, since these wounds were inflicted as part of the process of the sacrifice.