I'm guessing the first four photos were taken on the same day.
The first photo was taken about 140m (450 ft) SE of the current Newton Corner bridge over the turnpike. It is looking south on Park Street. The tracks on the right are coming from the current turnpike bridge whereas the train is headed for the old bridge over the B&A, pre-turnpike tracks. The house behind the backhoe scoop is visible in Google street view. I believe that when this photo was taken, the inbound trains were being routed over the new bridge as the inbound tracks in this photo have been removed.
In the 2nd photo, the trolley is at the old Newton Corner stop for outbound trains, now Charlesbank Road. It is about to turn right onto Galen Street. At the left edge of the photo is the construction for the new tracks over the turnpike.
In the 3rd picture, the trolley is in the same place as the trolley in photo #2. It may be the same cars.
I believe the 4th photo is an inbound train crossing the new turnpike bridge.
With near certainty, I believe the photo labeled, "Boston MTA, Work Car 40, Boston, Mass." was taken at Harvard Square, Cambridge, not Adams Square Boston, as labeled. The photographer is about 100m north of the current kiosk facing south towards the Anderson Bridge. The building with Leopold Morse Clothiers is still at the corner of Church Street and Massachusetts Avenue.
In the last photo at Watertown Square, I remember the trackless trolleys would loop counter-clockwise around the square. Today, they loop clockwise. Central-bound trackless would board at the same location as the trolley pictured. Harvard trackless would board at the old outbound platform on the other side of the waiting room.