Have everyone sign the written agreement then give everyone a copy for their own records so no one can forget if they get 40% or 50%. 

Sounds like you've already got a good track record you shouldn't be down on that.

Dont we all...Put some of your own nut into the game then ask this question a few years later when you're established with a proven track record. 

The lender will probably want security, so a lien will be placed on the property and recorded. 

In the event you record a sale the bank may or may not have the right to call the loan due.  

@Antoine Ferguson,Check with the county/tax records as @Michael Ablan suggested. 

You would first need to record your audio. 

However, at the start of 2020, records have been updated, as it now shows one owing $9000 and the other owing more than $11000 (turns out that other liens can be ultimately attached to property taxes if not paid in time—in this case the county wants to recoup expenses incurred in nuisance abatement and demolition).

I suggest building up your list to 1000-1200 records and send mail once a month instead of 250-300 weekly.

Essentially all you are doing is drafting a substitution of collateral contract and a mortgage on the new collateral will get recorded.