Two incredibly inexpensive things that every mid-century homeowner should know about. I'm not sure how I didn't know about them till tonight.
Decorator outlet covers (or paintable outlet covers)
Most people use them so they can paint their outlets the same color as their wall, but they're also great for covering those old-school, yellow outlets that were so popular back in the day (and cheaper/easier than replacing them with a new outlet).
Pre-cut to save you time and perfect for stopping drafts around any outlet or switch. The heat/AC bill should take a dip after putting them all around the house.