It's just occurred to me that I still have one last bush left over from my MX5 donor, and it needs replacing. It's a 91 NA MX5, and it's the bush in the top of a rear upright. What is really confusing is that some places I've seen say that it's the same bush for the inner and outer bushes on the top. That can't be right can it?

Can someone confirm what bush is used for the top of the upright on the rear? I'd probably prefer a top hat poly bush kind of thing as they're easier to work with.