HAs shown she was almost certainly the last River class in service anywhere in the world.
I believe that Dominican Navy had one River (ex HMCS Carlplace) in service as a presidential yacht and patrol ship until the early 1990s. At least my copy of "Weyers Flotten Taschenbuch 1990-1991" and "The World's Navies" by David Miller says so.
The drawing itself is, of course, great.