A couple of FBI Agents certified me as a Firearms instructor when I was a SC Deputy Sheriff. This was right about 1994 or so. They were carrying autos but one of the instructors loaned me his issue M-13 3" for the revolver portion of the course. He told me that he was allowed to hold on to it because he was an instructor. So at least a few agents still had revolvers in the 90s.
I now own a similar M-13. A more perfect carry revolver is difficult to conceive.