We're trying to buy a property which our surveyor reckons was extended in approximately 1990. Our solicitor is asking for a copy of the permission to extend, as required by a restrictive covenant from 1928 in favour of a named person and successors. If this document can't be found, is there really much of a risk of the breach being acted on? It's a 1920s property, with similar properties to either side, each of which have been/are being extended.