the perfectly lucid and literal FULL STOP acquire PERIOD as a synonym

The first use of the word period, meaning a full sentence, cited by the OED is in 1533. The first citation for the verb meaning to bring to a termination is 1595. Its use referring to the punctuation mark is dated 1609. The first citation for full stop meaning the punctuation is 1596.

So I guess y'all got plenty backup for historical precedence.