Along with the others, if there is a design, I know a machinist curious about possibly putting his CNC to use? It is the same proposition, though (not sure of minimum volumes). I don't know that I want to be the one to float 50-100 pairs. BBC, in NJ, doesn't seem to show anything about this type of thing on their website.
I can confirm the upper rear link has an outboard ball joint, on P85D. It looks like a press fit metal sleeve, and pivots as only a ball would. Going with arms w/o press fit joints would probably be a non-starter, from a DIY perspective. We can talk about how machinist work, and press fitting, isn't rocket science, but the truth is most haven't got the access. Another desirable feature, if going to the trouble, is a shim system where the arm comes in halves and could be given the 1/2", or however much people desire (how it's done for aftermarket Porsche). This assumes they aren't just looking to save their tires.