Foreign executors, administrators, conservators and guardians may discharge mortgages upon the records of any county upon recording with the recording officer of the county in which the mortgage is recorded a certified copy of their letters testamentary, or of administration, or of guardianship or of conservatorship. The certificate shall include a statement that the letters are in effect, and the certificate shall be recorded in the mortgage records. [Amended by 1973 c.506 2,44]