I'm just looking to use this for out second baby, however have misplaced the pursuit rain cover.
Please can you advise where I can buy another? Or one which would be suitable?
For the original rain cover availability, contacting the Silver Cross customer service would probably be easiest. They will either tell you where can you find it, distributors-wise, or offer one themselves.
Other than that, any universal rain cover, e.g. this one from Amazon, should fit. Or visit any baby store, they will show you universal rain covers to pick from - pretty much most standard ones should be just fine.