From my notes and data from NE Transit:
The MBTA Board of Directors approved on July 11, 2012 a $114 million contract with Alstom of Hornell NY to overhaul 74 Kawasaki bi-level cars with options to overhaul 32 additional cars at a later date. Wrecked car 1710 will not be overhauled and its repair is no longer an option. (NE Transit webpage)
On October 16, 2015, the MBTA Fiscal and Management Control Board approved Authority for Action for the overhaul of 32 additional Kawasaki coaches (750-781) for $32.1 million, increasing the total number of cars to be overhauled to 106.
First group of coaches prepped in October 2012. First five coaches assembled and
placed on Valley Track at BET by 10-27-12. There were 716,739,743,1701 & 1704.