Even if I redrawn it from scratch I'll still put the as a remix since I was strongly inspired by.

What I've changed :

-Added screw holes, so you can screw it in place with #4 or #6 -I also put a taper on the spike and on the key so they can't be pulled out -Some chamfer and fillet to make the thing look nice and be easy and fast to print ( I print them at 100mm/sec with no issue )

Those damn thing cost 60$ / 10ft in hardware store in Canada, if you're patient enough to print them you'll save some money.