Historic restorations can often be improved, but only where it can be done safely. Old retouching and fills may be reduced or re-integrated to improve legibility, provided this does not introduce new risks. Structural interventions—such as linings or patches—may also be reconsidered or, in some cases, reversed where appropriate.

All such work must be guided by condition, material sensitivity, and the likely impact of intervention. The aim is improvement without creating future conservation liabilities.