If it's clearly damage not covered by insurance or warranty, I'd probably drill very very small holes to mate with needles to reinforce the break. Possibly even using a high wattage soldering gun or plastic welder to melt metal mesh into the plastic to surround the break. Requires very steady hands. I've done similar plastic repairs for car headlight mount tabs and RC but I have never tried this for a more delicate gimbal...and unsure how calibration factors into such a repair. Just a wild suggestion.