The drop targets on the DE Simpsons I'm restoring were rather balky about the "drop" part, so I pulled the whole bank. On the backs of the targets, where each one slides against a switch, was some orange substance which I presume to be some sort of lube. This must have been what was causing the targets to hang up, as they drop down quite freely out of the machine. I'm assuming this lube/goop shouldn't be on there, but just wanted to make sure. The plastic targets should just rub against the metal switches, right?