All alterations, additions, or improvements upon the premises, made by either party, shall become the property of the Landlord and shall remain upon, and be surrendered with said premises, as a part thereof, at the end of the term hereof.

The safest thing is to give your notice to vacate or surrender possession, wait out any time periods (six months for tax certificate, none for tax deed) and then file your ejectment lawsuit.

Personally, I filled the yard with Round-Up last year before ultimately surrendering to the weeds that just seemed to keep thriving until now when I hired professionals to handle it. 

Without getting to far into the weeds...I had to file bankruptcy (chap 13) in 2015, in which I surrendered a mortgage.

He says most lenders will look to see that there are taxes paid so title must have been surrendered. 

I got the living roommates to surrender keys, surrender security deposit, and sign a document.

If you surrender the policy, you get that back.

I'm also confused on the "brick foundation" concept as mobile homes (even those surrendered as real property) are still installed like mobile homes on concrete blocks and not stacks of bricks.To make this deal work you need to look at the total real property income (in this case the four homes as rentals) and not put any additional value in the potential of the four additional homes as I'm sure the city will probably not let you add them unless they are in the original lot count for the park (as evidenced by the Certificate of Zoning).

Who were the other members and why did they surrender their ownership to you?

The part of the lease that pertains to this states: "The Tenant(s) agrees to keep premises in good, clean condition, - to make NO alterations, including painting; to replace glass broken or cracked as a result of Tenant’s neglect or careless use of the premises, to repay the Landlord the cost of repairs made necessary by the neglect or careless use of the premises by theTenant(s), and to surrender the premises at the termination hereof in like condition as when taken, reasonable wear by the elements and ordinary wear and tear excepted."