Joe, for modeling purposes, you can probably pick up cans of Testor/Model Master CNW Green and Yellow. I have a couple of friends at Atlas that verified they used the CNW paint colors for their Housatonic models. It looks spot on for me for color match.
I have not seen the boxcars recently. The last time I saw one was about 6 years ago.
The caboose is on the siding next to the engine house in Canaan. I have not seen it on a train in years either. They used to use it primarily for long backing moves.