Good news! I have now established that First Rank did continue beyond the first three volumes in the binder I have to hand. I have located a copy of Volume 5 Issue 10 (a “Special Issue” – one of two), which take us to July 1982. Somewhere in my clutter, there is another binder (which accords to my recollection).
In the meantime, publication has now reached Volume 2 Issue 5.
Link: First Rank