B&M was so dysfunctional through the 90's, they dropped cars anywhere they could. While this car would not have seen service in the 90's, the weathering level indicates it was long since abandoned. Cars like this literally littered the railroad in Boston at their Summerville yard, Waltham, Ayer and other towns with any need (or capacity) for storage.
In fact, if you check the photos area of nerail.org, you will see they didn't start scrapping in earnest at their Billerica yard until 1996.