Wut? Paperback allows you to get any manga from scan sources like Mangadex, with reading list / read status support, and is available on the App Store.

Not always, but quite true with iFixit in general.

I’d say to check directly at iFixit store for this kind of spare parts in general. Not cheap, but it’s most of the time genuine parts, and if not, pretty good quality ones.

Edit: https://store.ifixit.co.uk/products/lenovo-thinkpad-p51s-p52s-t470-t480-t570-t580-and-tp25-replacement-battery?pk_vid=43e4d3fac8f397091690269538cde128