Hi Doug,
The Stanley book has a rear pocket containing drawings of Locomotive 14 and one of the newer class of coaches. The Wallace book has a couple loco drawings that might be useful - especially the newer and older classes. The April 1947 issue of "The Model Craftsman" magazine has drawings of loco 14 and two classes of Laconia coaches. Frank Kyper and Lee Rainey's book "East Broad Top" has drawings of oldest class of BRB&L Laconia coach. Other EBT publications have drawings of some of the other classes of BRB&L coaches. Some of the ET&WNC publications (mostly the ET&WNC Hist Soc magazines) may have useful coach drawings too, but I don't recall this for sure.
Hope this helps!
Best Regards,
Glenn