|Good to hear you managed to work it out...|
Did you have the actual maintenance/repair manual/guide; or just take it to bits on the fly?
Often useful to make a few notes as to how ribbon cables etc. pass over/under assorted parts... as you start to disassemble the innards. Even make take a few pics too?
On some laptops too the screws may vary in size and even style and not be obviously different to each other initially. Apple has various screws used to hold the base on some of its Macbooks that "look" the same - but aren't quite. It is important to note which comes from where and that it goes back whence it came. Many make a simple sketch/drawing with each screw etc indicated on it; and scotch tape/sellotape the screws as they remove them to the appropriate place on the sketch/plan.
Even some hard drive brackets (on desktop/tower PC system) may have slightly different screws to the rest of the unit - even thought they look the same; and some older hard drive screws are slightly different between makes of drive; which why they often came with a set of screws to match the drive.
I have a wee box with three different types of screws for various hard drives. They all (from about 10 years or so) look the same - but each set/collection is slightly different to the others...