The halves are joined!
Now I have to let the epoxy that I used to fill the holes cure for a few more hours, then figure out a way to drill the new holes. I want to drill from the inside out, but that will make it hard to hot the old holes. There's no requirement to do so, of course, but it seems like it would be cleaner looking. I don't want to go from the outside in because it will push the hinge away and make it next to impossible to drill a round, accurately placed hold. Maybe I could do just a few inside outs and count on clecos to hold the hinge in place for the outside in drilling, but I'm dubious on a favorable prognosis.
There also quite a bit of epoxy that needs to be cleaned up on the holes, and the original installation of the hinge had 1/4" or so holes drilled in it and epoxy used to help the rivets hold it in place. So.... good progress, but plenty more to do yet.