It would be Class H for a through coal train and between 1936 (or earlier, I won't bother to check that) and May 1950 that would have been - viewed from the front as you would see the lamps on approaching train - one lamp in the centre of the bufferbeam and another above the right hand buffer. From May 1950 (in case you are interested) the Class H headcode was altered to one lamp above the centre of the bufferbeam and another at the base of the chimney/on the top lamp bracket but in any case a