There’s an old engineering meme about wd40 and duct tape. It’s really true. The dial mechanism on the rotary gruebox was slow and balky–running maybe 1/4 the speed it was supposed to, and one shot of wd40 and it’s running right as rain.
Contrary to popular myth, wd40 isn’t a lubricant exactly. It’s mostly a solvent with a little bit of lubricant. The solvent dissolves whatever’s gumming up the works, and the small shot of lubricant gets it running smoothly again. It’s not a replacement for proper lubrication, but it’s amazing stuff nonetheless.