i'm in the middle of remodeling a 1912 home, 2 storey + attic is being utilized now as well. its being completely gutted and rebuilt, insulated with "Spray Guard" a spray foam giving a 95% heat retention for 3 inches. i'm not sure if the "through the attic" method is used anymore, but if it is, good luck!! as for the 80 year old trim, our friend MDF can duplicate that in ways one couldn't imagine!!