I'm told NB Southern is lending 3 engines to the Montreal, Maine and Atlantic (MM&A) to help them in Northern Maine. Friday night's westbound is said to have 6 engines and be 9000' long. This must be an NB Southern record, as that is well over 100 cars!
The last time I can recall NBSR loaning units to the MM&A was in the spring of 2005 when NBSR 2319 was loaned. I posted two of Travis Bragg's videos a while ago. Here's one of them.
Keep in mind NBSR recently loaned their Jordan spreader to the MM&A too.