I wanted to make a modular pistol stand that I could customize for each gun. Each stand requires three pieces - a universal base (this thing), plus a customized vertical muzzle support and pistol grip base. I've included an example muzzle support/pistol grip base for a SW99 pistol. The customizable vertical support and grip base thing can be found here: https://www.thingiverse.com/thing:3685566. You simply need to measure or lookup some basic size information and Thingiverse will spit out a customized STL for your pistol.

The universal base should fit most pistols. It has about 90mm worth of adjustment for the length of the pistol, and can accommodate grips up to 40mm wide. The bases can be clipped together to hold multiple pistols.

The universal base comes in four flavors - single, left, right, and center. The single base is just that - a standalone base with no hooks to connect to other bases. Left, right, and center models have hooks to attach to the base next to it. Left and right refer to their smooth sides - as if they were bookends.

This model uses Daniel Upshaw's excellent roundedcube.scad module. You will need to download and place it in your openscad library if you want to mess with the scad files. https://danielupshaw.com/openscad-rounded-corners/