This design looks familiar
Fixing your bumper problem should be simple if the claw will still work with the bumper there.
Just bolt another tube across the front to provide "frame backing" and you'll be good.
What is the claw made out of? We made ours out of plywood, fiberglass, and chopped carbon fiber in '07; it was somewhat of a tour de force for our team at the time...
GL in Sactown!