oldravendale
Western Thunderer
It's strange how the majority of us paint our locomotive valve gear black or a variant of polished steel. When looking at the film I noticed around 02.58 when the loco is reversing around it's train the close up of the valve gear reveals the moving parts and nearby areas (piston rod, connecting rods etc) to be an oily light rust/bronze colour.
I loved the film too. By coincidence again (we must stop meeting like this) I was at Loughborough today for the "Last Day of BR Steam" commemorations which they did rather well with 70013 on a non stop Leicester North to Loughborough, identified as 1T57 and painted nameplates - however I digress. During a tour of the shed I noted the same thing as far as the colour of the rods valve gear was concerned and it is due to the thick grease of a golden colour used to protect the bright steel. In fact, when clean the gear is bright, but we'd not be so crass as to paint the rods on our locos silver, would we, but that's probably true for a loco ex works. In fact my photos show that, when locos were "bulled up" for specials the rods were polished steel. It may well have been common practice for sheds to coat the rods and valve gear in grease to minimise rust.
Maybe.....
Brian