6205 emerged from a Heavy General repair in May 1938 with only two sets of valve gear driving the outside valves directly and the inside ones via rocking shafts from forward extensions of the spindles. The most noticeable alteration was to the motion brackets, which were given extra support as seen in this photograph taken when the engine was in store at Willesden during October 1961. Above the platform, two holes had been cut in the cover box over the top of the motion bracket. The drawing schedule for the alteration called for new leading splashers, outside valve rods, combination levers, connecting links and eccentric rods as well as modifications to the connecting rods and crossheads so that needle roller bearings could be fitted.


It appears that this alteration was a trial undertaken before modifying the remainder of the Class. In May 1941, though, it was minuted that the experiment was satisfactory but that 'in the [wartime] conditions then prevailing it was not desirable to convert the remainder'.

Note that the engine had new outside cylinders without sighting plugs, the cylinder clothing had oval access panels, the cylinder cocks were steam operated without long drain pipes, and later pattern sandbox filler lids were fitted.