Value for a MHP is NOI / 0.1 (10% cap rate) for a well run park.  

perhaps your county is small enough, and it happens pretty seldom to the point that they dont bother keeping an actual 'running' list of them. 

Overall though, I view this process as a 10-20 year plan which allows me to retire and just run my properties.

It'll give you direct access to the MLS which will be invaluable for finding deals or if not, running your own comps.  

It's been a while, but I did run the basic ROI on my current parcel with two homes.

Hey everyone, I'm new to the forum and wanted to take a moment to introduce myself.I run a small analytics consulting business in Boston, and develop data science courses for several online education platforms.I'm interested in real estate investing as a means of diversifying my portfolio and providing additional streams of passive income.

Run your numbers.  

I'm starting to get a little bummed out, because I'm always busy working, but nothing has converted recently, so I feel like I'm running with my head cut off.

Each entity will have to essentially run separate depreciation calcs every year. 

You really need an REI friendly lender to run numbers.