Boston Revere Beach & Lynn MU coaches.

Since receiving my copy of "Narrow Gauge The Story of the Boston, Revere Beach & Lynn" my interest in those strange little cars has only increased. I would like to model at least three of these cars in 1:20.3 scale. I have a few questions and I hope some people have some answers. First does anyone have any information or plans on the Brill 177E2 model truck used to power these cars. Next is how were the 7 trailer cars used? It is stated that the cars were not equipped with control stands and it also says they had Brill 177E2 trucks but lists them as having no traction motors. That brings me to my third question. If they were not equipped with traction motors why would they have been equipped with the Brill truck? Forth question what kind of trolley pole equipment did they use and last what is the rack on the roofs of the cars? Is it just a walkway?