If you follow the dropbox link below (and assuming I have set set it up correctly) you will find an several images including one commemorating amongst other dates the closure of Castletown station as a block post. The cabin on the former MGWR main line, between Mullingar and Athlone, remained in use to operate signals protecting the adjacent level crossing with occasional movements operating over the line until the late 1990s.
https://www.dropbox.com/sh/q0oq7w9xt0sc ... swTsa?dl=0