Brockton station
It may be an auto-parts store now, but whatever this building was originally, it almost certainly received deliveries by rail. (North Montello St. in this area is lined with old industrial and commercial buildings for which that must have been true, including an old multi-story Grossman's lumber.)
Montello station
Ooh, what have we here? It's an MBTA bus, in Brockton! This route, #230 Quincy Center–Montello, is a remnant of the old Eastern Massachusetts Street Railway, which operated a large network of bus routes in several South Shore communities including Quincy and Norwood. The 230 for many years stopped at the Holbrook/Brockton line, since Brockton was not in the MBTA district and has its own bus service, but when the Old Colony commuter-rail service reopened, the bus route was re-extended to Montello station to provide connections with the train and give the bus drivers a better place to lay over. BAT buses do not enter the station but serve a stop on Spark St. east of the station.