Calculating Symmetries in Newman-Tamburino metrics
  In this paper I show that the Newman-Tamburino spherical metrics always admit a Killing vector, correcting a claim by Collinson and French, (1967 J. Math. Phys. 8 701) and also admit a homothety. A similar calculation is given for the limit of the Newman-Tamburino cylindrical metric. 
John D. Steele