MEC mystery photograph

There is a photograph of a MEC freight train from August, 1949 which has my curiosity. The caption reads that it is a mixed train heading to Dover-Foxcroft. I do know of any such service on the Dover-Foxcroft branch. There was a mixed train on the Harmony branch, but that ended in April, 1949. Does anyone have any information on this photograph?

Can you post or provide a URL for the photo? I can't promise results, but someone might get some ideas.

I cannot provide an URL. The photograph in question can found on page 81 of John Krause's "Trains of Northern New England" published in 1977. Though I have seen this same photograph and caption in another book.