After searching the net for a while, I determined that there's no good info available about how to arrange the plumbing for this purge line. Some perusing of the Jeg's website found this little fitting. It's a tight-bend 90 degree fitting that looks like it'll just do the trick. It's not an actual AN fitting to aircraft specifications, but this is going to be under pretty much zero stress, so I think it'll be just fine in this application. I do see, however that I'm going to have to redo the line going to the right port of the fuel selector valve. No big deal. Now that I've got that drawing to work from, it should be easy to make another one.