Type 8 trolley built by Breda is rolling through a bit of the T that is a throwback to the trolley era rolling in mixed traffic. Plans being considered may alter this view in the future.
The MBTA is very dear to me. The first trains I ever rode as a toddle to teenager were those of the "T" Here is a collection of MBTA Subway and trolley I have found on RP from the 60's thru today.