Not being a history buff, I'm sure someone could correct me. But my impression is that there has not really been "a-mil" vs. "post-mil" in the Reformed world until the 20th century. Instead, there was Reformed eschatology in general vs. the "chiliasts," or what would be comparable to pre-mils (not dispys). It seems that both amils and postmils point back to various Reformers through history to buttress their position, but I don't believe the amil/postmil distinction was really defined to that degree. There was a general thought that Christ instituted His kingdom at His first coming, and that He will reign until His second coming, and then the eternal state. That's the basic outline of both amil and postmil eschatology -- the difference is in how much earthly success Christ's kingdom has before His second coming. The Puritans also saw a mass conversion of the Jews, which is the particular version of postmil thought outlined in Iain Murray's "Puritan Hope." But that's probably the closest to any defined postmil thinking.
Rod Kirby, Ph.D.
Dominion Christian High School
Marietta, GA
dominionchristian.org