with the deskpi Pro I routed a channel then slotted the 128x32 into it, had I been careful that should have been all I needed but ended up using some damping material to hold it secure and reduce the light bleed too

easiest thing I've found for screw mounts is to solder the unit to perf-board large enough such that it can contain any circuitry but also with enough meat to drill fixing holes etc

you can also get fancy with 3D printing and/or CNC