My boyfriend found this treasure at a rummage sale in Seattle this past summer. The thing I like about it the most is that it is made of steel. Unlike Aluminum which leaches into food and is rumored to cause health issues over time, steel is safe. It looked really awful with some surface rust and grease build up, but have no fear, these items can be removed and the popper will be good as new. Here is how to clean up pots and pans that you find at rummage sales. This applies to steel, cast iron, and porcelain on steel. This does NOT apply to Aluminum. 
First you will need a potato, table salt, and fume free oven cleaner. Cut the potato in half and dip it into the salt. Without adding water or anything else, use the potato and salt to scrub the rust off the pan. You will find the rust combines with the salt and potato starch, coming off the pan's surface. If you need to, you may cut a thin slice off the potato and repeat the process until all the surface rust is off. Rinse the pan and dry it with paper towel or allow to air dry before moving on to the next steps.Spray the pan with Fume Free Oven Cleaner (I get mine at my local .99 cent store). Allow the pan to sit for a time and the chemicals to bond with the grease and build up. I let mine sit for 15 minutes. After it has had some time to work, I wash the pan with a nylon scrubby. If I find there is still build-up, I will repeat this process until the build up is removed.
Finally, wash your pan and dry as usual. As you can see, I made a nice bowl of popcorn as a reward for my efforts. Total cost for this pan? $1 at a rummage sale plus some table salt, a potato, and a can of oven cleaner and good old fashioned elbow grease.
