I don't think you can qualify unless you have land with no mobile homes on it that could be ground-leased to a QOZB set up under a QOF. You already own the land in the Opportunity Zone, so that would not be qualifying property and the business of running the park is already in operation. If you could land lease some vacant ground into a new structure, you might be able to set up a separate business in that zone, but that would be better operated by an unrelated party to qualify.