Why the straw and chalking?

Peter Kerslake says "This fine view of 7252 on shed at Radyr in her Welsh homeland shows the enlarged bunker capable of taking 5 tons together with the raised footplating over the cylinders, two features which were embodied into the class when they were rebuilt by Collett at Swindon, this particular engine being so rebuilt in 1939 from one of the original 2-8-0 design of 1912 and which had been numbered 4210.
7252 was destined to be one of the last four of her class to remain in service, being withdrawn in company with 7205, 7248 and 7249 in 1965.
Intended for use mainly on South Wales coal and mineral freight traffic duties the members of the class regularly ventured away from Wales on such duties, even running up to London and down to the West of England, with three even being used for a while as banking engines on Dainton bank and working from Newton Abbot Motive Power Depot in the mid 'forties.

The massive bulk of Welsh Heavy Tank 7252 takes up virtually the whole turntable here at Radyr in early 1961, this view showing the substantial coal bunker and the sheer size of the locomotive, 7252 having been one of the third batch of fourteen rebuilt from members of the "4200" class in 1937 with the majority being based within Wales.
The chalked inscription on the smokebox door seems to read "Countdown to St. Davids Day" but what that is caught in the smokebox handrail is unclear to me!
In its glory days Radyr had over fifty locomotives on its books, all Tank engines of various classes, the depot being elevated to principal status in January of 1958 when Cardiff's Cathays depot was reduced to sub shed status."