Not a difficult shape to work out with a set of quality calipers.
Or.
Put it on a piece of paper.
Trace the outline as tight as you can get it.
Scan it with a flatbed.
Drop it into a raster to vector convertor like this.
https://vectormagic.com/
Dump that into a simple CAD utility and do an extrusion.
Export CAD file.
Give file AND the single piece to machine shop and I'm sure they will tweak any minor stuff it needs.
EDIT: or send it to fanaudical.