Ok I think I now what you are saying, first off if am way in left field with this I am sorry but with outs a picture it hard to know,
Have you ever wet molded a round corner before, if not I will start with the basics, the piece needs to be cut a lot larger than the end size reason is when molding the corners they are tuff so you have two options you can make a mold of your lap top out if wood and then make out side clamp type mold this works nice but is time cosuming, the best way is to make the top piece
Bigger and then when molding use small nails to hold the leather in place but when you get to the corners you make slits in the corners back of the finished size this let's the leather wrap around the corners better I can't post pics my coumputer is dead I am on my I phone.
But this is how you make a nice smooth mold and get those wrinkels out. Hope this helps
Josh