I am in the same boat except I can only find 1 bracket and that's the one I am using. I don't know if mine even came with a second one. Should it have? Probably... did it? I don't remember.
I would be happy if they just provided a 3d model so you could make the part... it isn't being sold anywhere, so that would be the most logical way to handle it. If I find my other bracket so I have a template, I'll make a 3d printable version and upload it.