I've done this on quite a few now, but I use rod ends with boots on from
McGill Motorsport:
In many cases the bracket on the control arm can be recovered with a good clean and a soak in evaporust, although when I eventually figure out how to print nylon I'll probably make a bolt-on bracket. I cut the ball off the original bracket and drill out to M6, then the rod end can be bolted on using a nyloc nut. Same process with the rear arm too.
Mike and I did try an alternative strategy with another one recently which was to buy one of the cheap chinesum sensors for the A6 which comes with an arm and bracket, then recover the bracket, ball joints and bushes from that and fit them to a D2 plastic arm. It was pretty fiddly but worked ok since I didn't have any of the rod ends to hand.
A friend in Germany has 3D printed the bushes from polyurethane which was an interesting idea, then recovered the original bracket and ball joint which were de-rusted, re-greased and reassembled.