Not certain why you would need a bridge to connect the screws tot he cladding hole. You may just need to take off more material from the top edge of the slot to allow the plate to slide further down the hitch and line up the holes. The slot was based on Tone's hitch which I'm not sure if that's what you have or not.
ABS will not crack unless you run over it or something. You can drill it, sand it, file it, and machine it if you have to.
I was able to put a non-locking pin in it. I suggest placing the plate in place, installing the pin, then installing the screws from plate to cladding. HTH. ron