If you have a boom strike, the tail boom can be straightened by pushing a 3/8" dowel through the tail boom.
If you let the Corona come down too fast it may "bounce" off the ground and break a main gear tooth and/or trash a bearing. So, the main gear should be checked periodically for missing teeth and the main rotor shaft bearings should be checked for smoothness.
Be sure to check HS-81s for broken gear teeth after each hard crash. They may rotate properly through the whole rotation, but they may have a broken tooth somewhere.
I consider the HS-81 gears a "sacrificial" part...they break to prevent other things from being broken, and at $3-$5 a set they are fairly cheap.