I think most all of the steam chests were blackened, not painted. They will look flat compared with the rest of the engine. When new they were probably a deep black but most lighten with age. They were probably done with a hot black treatment.
Cold bluing compounds don't match. At least I haven't found any yet that do and have tried anout half dozen of them.
Maybe a gunsmith who restores guns could help here.
Pete
I've seen a lot, maybe too many, of steam chests recently. They do seem to look different from the boilers. Having said that, time for a trip to the basement to check a few .............. and from what I see, it looks like Pete is right. On the 224, the cykinders don't have the sheen of the boiler. Three others from a 1666, 2026 and 2018 also look flat.
I have a 1666 that I fixed up for a layout for my grandchildren several years ago, before I got into serious learning about these beautiful engines. It's now home - teenagers these days are not easily interested in trains. Naturally, the whole thing is satin black, and that is the one I'm keeping for my collection (i'm collecting the 1946-49 catalog items). I think I'll swap the steam chest pon that one for the one I mentioned above and sell the painted steam chest. I'll mention that it was painted, but I have a feeling that a lot of the eBay buyers don't care as long as it looks better than the damaged item they are replacing.