762. Lost or destroyed documents.

Where any assessment to tax1 or any duplicate of assessment to tax, or any return2 or other document relating to tax, has been lost or destroyed or been so defaced or damaged as to be illegible or otherwise useless, the Commissioners for HM Revenue and Customs may, notwithstanding anything in any enactment to the contrary, do all such acts and things as they might have done, and all such acts and things so done are as valid and effectual for all purposes as they would have been, if the assessment or duplicate of assessment had not been made, or