Thanks for a peachy article. I've improved the 1940 vintage casements in our housing as easily. They are prefab and really good, and aren't any worse for their 70 years. I learned a gimmick for sealing: Put a bead of caulk on the pane. When the pane closes, it "squishes" the caulk and makes a better seal. Wipe off the extra caulk. You now have a form-fitted gasket. Since the steel construct is already stronger than any storm window border out there, I simply put 1/8" paint artifact cut to the dimensions of the old pane surfaces- one crosswise and two flanking. They virtually conceal the gasket. This has improved elegance of our windows. Thanks again for the article.