SAM Coupe Screws


Ive fished out my old sam out of the loft, it still powers up fine and id like to recondition it, but the screws are missing.  Ive searched online for videos on teardowns etc.  But none of the videos or pictures show the screws being removed.  

Is there anyone out there that knows what kind of screws would be replacements on the underside and also for attach the keyboard to the case please?

Many thanks,