Private Reverse Mortgage / Lifetime Lease

[Marc M.]

My neighbor, a 68 year-old guy with no family or kids, started a renovation of his house and never finished it. The property is located 2 blocks from the beach in Santa Monica, needless to say it's worth a lot...even it's present torn-up condition. The land itself is worth about $500-600K. He currently owes about $350K in a HELOC he took out to do the renovation, and then ran out of money....8 years later it's mostly bare studs.

My idea: Pay off his debts, finance the renovation of house, and let him live in it for the rest of his life, and he would be responsible to pay the taxes, insurance, utilities, and basic upkeep. When he passes or if he defaulted on his fiduciary responsibilities, I would get the house . This would be similar to a reverse mortgage, but private, and therefore uninsurable by the federal government. So, to give myself some assurance I would prefer to take title of the property....but if the property taxes are reassessed the guy will not be able to afford them. He has owned the house for 40+ years. So the question is: what is the best structure to buy the property (or refinance his existing debt) that protects my interests and the title of the property? A deed trust? 

Looking forward to hearing your thoughts...

-marc