Chessie - paint dates

[Southern Rail Fan]

Is there a source to find out when (or even if) B&O/C&O/WM units were painted into Chessie colors?

Browsing through pictures, I've seen plenty of units that held their B&O and C&O (and to a lesser extent WM) paint for a long time. It looks like a few may have never seen Chessie paint. I'd like to have a source to know when and if repainting happened. It would be good to know what paint some of units I'd like to run were wearing at a given time.

[skipgear]

As far as I know there is no real guideline. Not sure if they came in to be shopped specifically for the repaint or it was done when a major service came due. I think the best answer is search for photo evidence and replicate that.

[Sizemore]

If I were to give a rough date, I would say sometime after 1973/1974 when you would begin seeing WM units painted into Chessie, however that would be few and far between and, as noted previously, when shopped.