It could mean anything from simply starting it up to replacing all fluids, spark plugs and filters, flushing out old coolant, replacing all belts (it's a chain cam engine), cleaning the carburettors, servicing the carburettors, replacing the points and leads.

Remember to look in the boot, lift the carpet and check the joint between the sandwich fuel tank. They have usually rusted here and the whole tank needs replacing. Any smell of petrol, replace the tank.