I've got an approx 30 year old Tappan deep freezer that's starting to accumulate heavy frost on the inside. The ice forms at the top, and gradually accumulates down the walls. I'm assuming the gasket is toast. I haven't found the exact gasket yet, but I'm assuming it's gonna be about $125-150. The freezer still works fine. Does anyone know of a cheaper solution to try like a universal gasket? I'm a little leary of throwing $150 at a 30 year old freezer. Ice is building up almost uniformly along the top edge where the gasket seats.