Looks like you need a Tenant in Common Agreement. Call some places and see if they are familiar with the term. Ask if they have ever done Tenant in Common Agreement….. it’s very common on the west coast (California) but it’s still a new thing out here…….
Tenancy in common
Tenancy in common is the default form of concurrent estate[where?], in which each owner, referred to as a tenant in common, is regarded by the law as owning separate and distinct shares of the same property. By default, all co-owners own equal shares, but their interests may differ in size.
This form of ownership is most common where the co-owners are not married or have contributed different amounts to the purchase of the property. The assets of a joint commercial partnership might be held as a tenancy in common.
Tenants in common have no right of survivorship, meaning that if one tenant in common dies, that tenant’s interest in the property will be part of his or her estate and pass by inheritance to that owner’s devisees or heirs, either by will, or by intestate succession. Also, as each tenant in common has an interest in the property, they may, in the absence of any restriction agreed to between all the tenants in common, sell or otherwise deal with the interest in the property (e.g. mortgage it) during their lifetime, like any other property interest.