In a festive mood, the ladies of the Farndale Avenue Housing Estate Townswomen’s Guild Dramatic Society mount another assault on the classics with their stage version of “A Christmas Carol.” They enthusiastically portray a dizzy array of characters from the Dickensian favorite (and a few which aren’t), engineer some novel audience participation while bravely contending with an intrusive PA system, and — a real Farndale first — wrap their vocal cords and feet around two original, show-stopping songs.