Decided to attempt my first re-sclera using this eyeset, turning it into mswn's, but I'm not sure if this upper black part highlighted is normal or not. The psd looks easy enough but I don't know a thing about creating or putting a new sclera on eyes

I think it's just there to create the illusion of shadow over the eyes. If you have a look at the EAxis eyes, there's no shadow there.

Some simmers prefer the shadow look (it often adds toward realism), others prefer eyes with a full iris and brighter sclera (can be better for photoshoots when sims do eye angles, but can make the sim look a bit more cartoonish, so it's a bit of give and take).