In your situation changing lock would not have made any difference. The thief broke your door. No block could have prevented actual damage to the the work. People who have CH751 keys all know that those keys will fit any outside storage on any trailer. And I think most people who have CH751 keys are campers themself and are respectful of other campers. There are exceptions but as a general rule we've never had any problems at all ever if any campground with our storage compartments. Considering yours was at a storage facility I would say think theft knows nothing about campers especially the CH751 key. If you try to reinforce the door a thief will just create more damage to get through the door. Keep it the way it is and check with your storage facility security.