Actually have been looking into this for quite a while and wrote several articles on rakes, the rules and the history of raking. You'll find, as far as I can tell, the first rake ads in the 1920s for greenkeepers. Maybe the British or Irish are earlier, but I haven't seen it (yet). I have scoured photos of championships and you will find evidence of scruffed up bunkers without obvious raking until the post WWII era, when it looks like rakes were used regularly during play. Even then, you will not see rakes in the photos of courses during play until the mid-late 1950s. So I would date that as the end of civilization as we know it in the post-Sputnik era, i.e. 1957+.