I have seen old windows updated to tiltable sashes by removing the weights and cords. How does one achieve this? Can you give me step by step instructions? Do you know of any sources in the Norfolk, VA area that carries the parts necessary for the conversion? The windows are at least 105 years old and I don't want to replace them since they are not rotted nor in bad condition. I want to improve the energy efficiency. All of the sizes are customed, ranging from 3'x 9' in the front and back parlors to 3'x 7' in the master bedroom and 3'x 6' in the other secondary rooms. The house is very cold and drafty there are a total of 44 windows.