Looking good there, Harrier. I believe I would leave the oil pan as you have it painted. I would think these engines were assembled, then fully painted and installed. I paid particular close attention when I pulled the virgin engine from my '56 F350. I am convinced the engine was painted yellow, water pump to bell housing and intake manifold to clutch cover. Even the original pressure plate had over spray of yellow paint thereon which tells me something. Accessories were probably added just prior to or during engine installation. Makes no sense to me why an oil pan would be different color unless it was some special rust preventive coating or paint. Knowing Ford did not care about rust at this time frame, I doubt if that was the case. I have a complete engine from a '56 F-100 and the intake, bell housing was originally yellow but the block and heads had been painted at sometime when the engine was overhauled.
Valve covers on both engines appear to have been a silver / gold, probably metallic . Years of heat cool cycles have made a color id impossible. i went back argent on mine. If not original, very close. Mine looks like those engines in the thread you mention. Hope I did not
Again, looks good.