Subway Cars of the BMT not any help. Only talks of unused motormens cabs and their conversion to "private passenger cabs" (remember them?) On page 13....."An extensive rebuilding program took place in 1959-1960 that included removal of the unused motorman's cabs and replaced some cross seats with longitudinal seats, 396 cars received this treatment."
Apparently the first 600 cars, 2000-2599 had the unobstructed front window.
I also believe that "dragging passengers" was not the problem people seem to think. When revised to be operated by a single conductor, did not all train doors to one side of the conductor close, then all doors to the other side, and then finally the conductor's doors. In theory all doors were to be clear and closed before the conductor closed his doors,