This is the top of the sample showing the wooden blocks that would have held the pulleys on the inside of the wall and suspended the sash weights by cord. A loose pulley is shown for comparison. How long the tapered square nails would have held the blocks in place while guiding 5-8 pound sash weights might have been problematical. The photo has been uploaded on its side for some reason that isn't readily explained. Click "View Original" to see photo in proper form.