From: Rabbi Moshe Sofer
To: Rabbi Eliyahu
The Chasam Sofer analyzes an ancient Torah scroll with highly irregular letter forms and extra tagin, ruling that extra crowns and most unusual shapes do not invalidate the scroll, but that a vav indistinguishable from a final pei renders it unfit. Because this defect pervades the Divine Names, which cannot be erased, and the scroll contains additional textual errors, he rules it must be permanently retired to genizah and never used again.
Source: Shu"t Chasam Sofer YD §265