Can't answer the question, but I want to throw in my two cents about Budds. They were reliable, alright, but I didn't like them. I grew up on steam and diesel conventional trains, and when the Budds came along, everything got kinda "generic" on the B&M, at least on the east end. They could move right along, though. I was in the cab of a Dover train [got on in Lawrence], and between Lowell Jct. and Reading Highlands, we hit 82 MPH.
The B&M also ran them as single unitson at least one train. There was a 4:50 PM departure from Boston, and the first stop was Exeter. Got the Granite Staters home fast from work, I guess!