Do you have any pics of your claws Jamie and the whole robot.
Not very good ones and not to hand at the moment but could possibly get some. Basically I've got four strips of 4mm aluminium (grade unknown), two for each claw, that connect between the linear actuator mounting hole and the claws. Kinda like the push-rods Calum's got but each rod is two separate pieces and bolt on to the outside of the claw like you said. The ends of the claws that mount onto the pivot rod in the robot are also little aluminium pieces with holes in them and they bolt on to the ends of the claws. So those ali parts will be the bits that fail first probably.
Doubt Carcinus is going to see too much punishing combat though so hopefully won't suffer too quickly. Unless I have a mad spell and enter it into the full comp at the next champs.