Mo. Rev. Stat. § 443.200
If any part of the property be real estate, the petition may be filed in any county where any part of the mortgaged premises is situated; if it be exclusively personal estate, it may be filed and proceeded with as in other civil actions.
(RSMo 1939 § 3452)
Prior revisions: 1929 § 3065; 1919 § 2224; 1909 § 2831