I am an SE newbie. I just got a nice vintage SE Gem and need some blades designed for shaving and not stripping paint off windows. My internet searches lead me to believe that there is only a handful of candidates out there....I'm wondering what your preference is and where they can be obtained. Should I be cautious about buying very old blades that I often see for sale, ones that were made many decades ago? Wouldn't these blades have disintegrated (or compromised) over so much time?