I looked at literally hundreds of cars in the junkyard a couple weeks ago for a similar adjuster; nothing.. Most are internal to the (sealed) headlights these days, and the ones that are outside (older, 90's cars) are rusted to dust around here. A decent CNC lathe should have no problem turning them from stainless, though starting with an off-the-shelf screw to get the head (phillips or hex) may help so it wouldn't have to be punched.. I was going to look into it this weekend if I get a chance; at least modeling the stock one in SolidWorks. I've got my headlight assembly in my lap as I type this. LOL
Playing with SolidWorks.. An M5 x 40mm SHCS is almost perfect to turn down into a ball end.. The hex socket is about the same diameter as the flat on the ball though.. It looks like it would work though, the way the ball pivots you'd still have access to the hex with a ball-end allen wrench. If we have some M5 SHCS's at work I'll see if I can turn one down on the lathe - it's not CNC and I don't have a ball turner attachment though.. Would be nice if the hex were one size smaller too. Actually anyone can simulate this with a drill (or drill press) and a file. I use my cordless drill and a file as a lathe all the time....
Just chuck it in the drill (don't damage the threads - sometimes I'll run a bunch of nuts down on the screw and grab those), get it as close as you can to a 7mm ball diameter, and polish it up with some 800 grit / 1000 grit paper..
The retainer ring seems to be for a 10mm shaft. McMaster doesn't have self-locking push-on retainer rings for 10mm shafts, but personally I'd use one of these instead so it's removable and reusable (without swearing or stabbing yourself), P/N 90967A160 in stainless:
Doing some more digging today; it looks like Volkswagen used the same bolts in their older Jettas, Sciroccos, etc.. But they're pretty hard to find apparently.
Though here's an eBay auction for some, $28 for 2 of what look almost identical to the Lotus parts.. (plus a 3rd that wouldn't be used) Nowhere can I find dimensions though, so just a guess at this point unless someone also has a VW they can take apart. Apparently none of the junkyard VW's I saw had these or I would have been jumping up and down at the junkyard..
Ebay searching "Volkswagen headlight adjuster" brings up a bunch of options, but looking like $15+ per screw to 'take a chance'.
Reproduction part -> http://www.airheadparts.com/vintage-...op-255941141-b
More edits.. Apparently BMW uses some similar screws for 90's 5 and 7 series cars.. Still no mention of thread or ball size though, but another option to look for if junkyarding ->