I see a lot of parks here in Kentucky and know several people that own them. The numbers sound really good so I believe you got a good deal, especially owner financed!! As previously mentioned I would consider lease to own (not owner financed) so if the lease breaks...aka missed payments..you would still own it and resell it. I know people who have done very well with this one b/c in the end they own the lot and rent it out.
Your obviously doing something right b/c you already own quite a few properties and are a lawyer so your smart enough to write your contracts to protect your investment no matter how you do it. As long as people see there is a new owner and nice changes are taking place you should have no problem filling it up.
I get offered fairly nice free mobile homes if I will pay the moving costs and if I owned a place like yours I would advertise I were looking to buy mobile homes or looking for freebies. If it comes down to not being worth much just offer to take it for free and pay all the costs, it works! You can pick and choose deals and upgrade over the next several years.
Best of luck.