You can glue acrylic together in a clear fashion. Basically you need to make the parts fit together very well, then run a bead of solvent (usually MEK) down the gap.
Plenty of instructions around the net, here's
[ Show youtube player ].
Of course you can't solvent weld acrylic directly on top of a metal case, but perhaps you could create some kind of rim or eyelets for the screws so they will not be very visble.