This isn't clear as it should be. Was Kerry a senator BEFORE he received an 'honorable' discharge? Or was his dishcharge (other than honorable) reviewed and upgraded along with the re-issue of his citations in order to be eligible to be elected senator?
He got his honorable discharge in 1978, under Carter.
He became Seantor in 1985, and he got his citations reissued, which presumably lost, when he was dishonorably discharged in 1972.