If a person has an original M21 in a 69 Z/28 with a code of say P9D17B, for example. If the lower drain plug hole has been, or were to be drilled and tapped for the Lisle magnetic drain plug, for the ease of draining and particle collection purposes. How many points would be lost for this modification on a 1000 point system? Would the judges think this was minor or say that an M22 drain hole should not be in an M21? Comments Please.