Here it is.
I’ve designed a bracket that will take a wishbone going into it or rather, the captive spherical bearing in a custom designed wishbone. It’s not easy to design a wishbone well – anything one makes that is adjustable invariably is weaker than the fixed part. However, this means it’s tricky to just got it right out of the blocks.
So, the plan is to design an adjustable wishbone, get the car properly set up by cornering force, then take the wishbones off, jig them and make custom ones that fit the jig. Saying that, here’s the bracket.
It’s been thickened to give good support for the bolt (so the holes don’t oval) and the holes in the back go into a bracket with a set of stepped holes, thus the bracket can be moved up and down to provide height-adjust for the suspension.