Actual mate on the physical chessboard

I am currently helping write a book on the history of the Laws of Chess. I am working with Stewart Reuben and Alex McFarlane, and while we plan to go back as far as we can, it will be the modern era (since 1924) which will be the focus.
In the book we hope to put in games that provoked changes, or showed that more work needed to be done. One such game is the Rumens v Mabbs game from 1959, which provoked an enormous amount of discussion at the time. The time limit was 36 moves in 2 hours, and both players were in severe time trouble. Rumens mated Mabbs with his 36th move, but his flag fell before he could press his clock. At the time the rules were a little contradictory, with checkmate ending the game, but the move not being completed until the clock had been pressed. Therefore it wasn't clear if White had won by checkmate, or had lost on time. On appeal the game was awarded to White, and the rules were amended to reflect this.

Rumens,DE - Mabbs,DJ [B84]
London Boys Championship, 30.03.1959