To start with the Sudarium and the Shroud have the same rare blood type 2% of general population. The chance of this is less then 1% given these were independent events one or two forged. In addiition marks on the Sudarium matching the Shroud which also makes the chance of forgery unlikely. The Shroud did not have a strong image until it was photographed so assuming it was forged over 700 years ago the forger had no idea that the evidence would come to light given high resolution photography of today.
Hi Alan
I was where you are now based on the carbon dating. There is a lot more evidence today then existed couple of years ago. I would be interested in you looking at the papers and presentation posted here to see if your skepticism changes. Here is a well researched book.