[Ron Wood]

As Howard stated, a rubber mallet is too resilient to provide the necessary impulse and momentum to move the receiver against the friction of the bent frame. You might try the following: Use a hard wood block of the correct width to fit between the frame ears. "Buckle" the toggle so that the wood block rests against the rear of the receiver rails rather than on the projection of the rear toggle link. Rest the front of the frame on a solid non-marring surface (the edge of a wooden workbench would work) and strike the wood block with a brass or steel hammer to drive forward the receiver (you might need an extra set of hands to hold the frame on the bench top while you wack away with the hammer). When you get the receiver far enough forward to clear the main toggle axle, remove it and raise the rear toggle link so that the T-hook will clear the frame as the receiver moves forward, otherwise the T-hook will jam on the frame and either shear off or prevent further movement. If you are successful in moving the receiver forward, once you get it far enough forward you can completely remove the toggle assembly and continue driving the receiver out. As Howard says, slow and easy is important. Good luck...such an effort is not for the faint of heart.