I took a look at this, since it's a week off for me from the Listener (numerical). Unless I'm doing something wrong, Guardian search often turns up nothing or incomplete puzzles for the early years of the Genius. So it's hard to tell if there was a preamble in the original or not. If there was, it would be something like "All clues have a letter omitted in the wordplay. These form a dedication in the completed grid."
12 across is poor. It should be two Vs (Czech) or two Ws (Polish). Otherwise quite fun, and a shame the setter isn't named.
I can't find any evidence that 2003 was a particularly significant anniversary for the pair?