26.0 to 31.8 mm Handlebar Shim

A 26.0 to 31.8 mm shim. I have a few bikes, & one Cygolite front light. One of my bikes has a 26.0 mm handlebar, so I have to tighten down the front light clamp a lot to swap it between this particular bike & my others. This is 19 mm in width, which is just about the width of the Cygolite front mount.

May be too narrow/wide for your accessories, but you could just edit the SLDPRT file pretty easily.