do an internet search for plaster washers from charles street supply in boston ma
they got all the info on they site how to use these things. restore the old walls, save for future generations
drywall is crap compared to plaster, even if its restored plaster is a thousand times better than plaster veneer drywall
blue board is vapor barrier, this is not what your wanting to do walls in rooms with , your going to get moisture problems and mold. you would want regular drywall if your going to go this way