I haven't figured out how to post photos yet. Sorry.
I contacted Danny - a seller on ebay - who has a trigger guard for sale, and explained my situation, along with wondering if his would fit my gun. He told me I should bend it to fit, that investment cast brass (like the TC parts) tends to be fairly malleable and unlikely to crack. He said the sand cast parts aren't quite as limber.
So, figuring I had nothing to lose, tried bending it. Let me tell you, stretching that thing 3/16" was NOT easy! I got it stretched but the angles were wrong. Once I got the angles right again, it had shrunk back to its original length. Using a different approach it eventually got there. I think I spent about three hours total on this puzzle carefully tweaking, trying again a little more, back and forth, cleaning and polishing, and then relocating the front screw hole.
Hopefully the data on investment cast brass being malleable will help someone in the future.