The next best thing would be a PAR16 120V 60W halogen bulb with E26 base (medium Edison) directed towards the popcorn storage. It's about the same size as an A bulb and will direct the heat to where you want it. They come in 10° spot or 30° flood; the narrower, the better to keep the heat in the area you want it. Sometimes these are available at home improvement centers, otherwise, light bulb specialty stores.
Don't forget to thank your wife for giving you a gift that requires repair or modification. She knows you need to tinker.:razz: