Update: Cleaned the script up a little. I have learned much more since the original version of the script was uploaded.

Since the LED matrix holders I have found so far aren't parametric, or won't fit standard pitch veroboard, I made my own in OpenSCAD. You can fully customize the height of the case, number of rows and columns, LED size, grid size, grid spacing and thickness of the bottom plate and outer walls.

Sample files for the most commonly used formats provided: 5x7 and 8x8 for 3mm and 5mm LEDs.

When setting the final height correctly, it can also be used as a jig for making LED cubes :-)

This is my first parametric thing I have uploaded together with the script, so please don't judge me too hard.