Here is how I did a road fix on mine when I lost it on the hwy between home and the first rest stop we made... I had forgotten to twist the locking tabs in the lock position..
I did get a replacement cover, but after 2 different tries at getting the correct one, I gave up and just made the one that fit the 'best' work. I had to use the frame they provided and just merged it to the original one. Works and looks fine.. If I ever do get one that fits the original frame, I can still use it too. Just have not worried about it enough to try finding one.
Mitch