Elspeth,
If the house has been wired in PVC Twin & earth Cable, the age of it is irrelevant,in fact the older pvc is better quality than the ones we use now, it would be worth having it checked as the Earthing would need upgrading and you would need a new Fuseboard ( Consumers unit) and possibly a few extra sockets installed as we now use a lot more appliances than when it was done, try to find a local electrician that a friend or relative has used,and ask him to give it a "periodic Report" this will highlight any work required, it will probably cost � 100 -�150 to have this done,but it is a thourogh check, good luck, Ray