Reviving this thread. Because of the sidecar, I was trying to fit the left side mount and it was giving me trouble. I'm guessing the PO must have wrecked and bent them. I fitted the right side and they go on with little trouble. So it looks like I'll have to do some bending to make the other one fit.
Thanks to all who posted tips and pics here, it did help. And I'm not sure if this post was during the time of some technical troubles, but I see replies here that I didn't see the first time around.
Justin - I've probably got the mount thing figured out but maybe I'll make it south someday and we can look at other stuff.
MrClu - on the last photo you posted, how do those connect at the top? If I go the ammo box route, one idea in my head was similar to the hangers at the bottom, but I wasn't sure about the top. Maybe a knob inside the box that threads onto a bolt on the mount? Or a piece with a tab that you can turn and hook the top rail of the mount? Both of those would make them easily removable. I'm on my phone but just can't see clearly if it's there.
Thanks again for the help and tips.