Mo. Rev. Stat. § 404.520: Custodian's rights in other property of beneficiary.

A personal custodian has no right because of designation as personal custodian to possession, control, income or proceeds of any property belonging to the beneficiary that is not transferred to the personal custodian by the beneficiary, a donor or a person indebted to the beneficiary, except as authorized by the court under sections 404.500 and 404.510.