Newbe, Questions on Mobile home deal. What should I ask?

Hear is the story. Yes it’s sunday and I feel like writing a book.

Last year I looked at a vacant rental propety FSBO that needed rehabbing. The owner’s wife told me he doesn’t have the time to rehab this property due to a job change and doesn’t want to pay to have it done. It has a nice size 2/2 rental house, a 1/1 garage apt. and 3 distressed mobiles on the lot. The property is set up for an additional 8 mobiles. It is on a large city lot and we were told by the neighbor that no new mobiles were going to be allowed. I didn’t go any farther with this property at the time. Assuming the value of rent on only on two houses and 1 double wide - repairs no deal. Owner not desperate enough. Asking $150,000.
I drove by two weeks ago he has for sale signs still out so I pulled tax assessment and sent letter of interest. He has called me back to set up an appointment. He is now asking $110.000 Pulled the mortgage deed information and he owns this free and clear. Owner told me that the big house has to have a new roof before occupency and he doesn’t want to do the repair. I had two contractors and maintenance man go through the houses and the only major work is the roof, ceiling repair in the kitchen, lino and cleaning. I have never repaired or invested in mobiles except to by notes.
I have a friend that is a seasoned mobile home rehabber and invester so he walked to trailers with me friday. He said that all three are all salvagable and estimated less than $5,000. repairs to all three. Hump! the numbers are looking alittle better to me. Next I went to the city planning inspector and he reaffirmed that the house only needs roof repair, all trailers can be rehabbed. He also told us that the park variance will still convey to a new owner and we can have 8 additional mobiles set up.

My first question is what do I need to know in addition to this about Mobile home park ownership. I’m sure there are liciences, permits and insurance questions that need to be answered? Where would I start?