Hanks, of course, featured as a goodie in one of those movies which have exemplified Anglo-American war-time collaboration for the current generation of schoolchildren. So it is in his Private Ryan persona that he has been asked to join the trans-Atlantic team of judges for the essay competition set up for British teenagers by American ambassador Philip Lader.
Irving, by contrast, is now everyone's baddie since he spectacularly lost a libel case which stirred up still darker war-time memories of German concentration camps and anti-Semitism.
Philip Lader's aim is to hand down more positive recollections of war to successor generations, by inspiring them to interview their grandparents and older neighbours in search of evidence and anecdotes about how our two nations fought and lived together. He had found that children here - like their American peers - didn't learn much about the last world war in their history lessons.
David Irving's motives were more opaque, though he seemed to be counting on his audience - in the courtroom and beyond - failing to access and weigh the hard evidence and living memory still available on the Holocaust. What was incredible about his performance, whatever his mastery of the archives, was his denial of contemporary material about events which occurred when he was barely in primary school.
I was a few years ahead of him. Not old enough to be a GI bride, but able to remember bombs and rationing and, later, those appalling grey and grainy newsreels of bodies piled high at Belsen, which were shown at all our local cinemas. Schindler's List was just an echo. It seems amazing now that young teenagers were allowed in, but it was thought important that we should see and remember, and we had lived trough the war.
So, as a grandparent now, I qualify as a source for the American ambassador's competition, and to form an opinion about Mr Irving's views on the gas-chambers. It is slightly unnerving to live in this borderline between memory and such a momentous slice of history as the Second World War. Memories can be both vivid and fallible, but we don't want them denied by blatant misuse of the evidence.
So I hope that any 15-year-old who approaches me for first-hand reports treats them with more respect than my own family. As a teenager, my son cut off any "boring on" about war-time privations by putting on a record of The Secret Policeman's Ball: ("That were nothing, when I were a boy..."). Now my six-year-old grandson simply asks: "Which were the goodies and which were the baddies?" (That's easy now, Tom Hanks and David Irving).
More seriously, all this reminds us of the importance of history, and of the proper teaching of events, interpretation, and the use of evidence. One of Irving's more frightening assertions was that Auschwitz was a myth, although he had never visited the site or looked at the evidence there.
But what do we mean by "myth"? I have another memory, this time dating only from 1989, when I read the first national curriculum proposals from Kenneth Baker's history working group. In the brief world war section it asked students to discuss both Winston Churchill and the Blitz in terms of myth. It makes you wonder if you are real.
I believe that the history curriculum is in better shape now, and many of the old empathy versus fact battles have gone quiet. Unfortunately, so has the position of history in the curriculum, now that students can - and often do - drop it before taking GCSE. It would be ironic if David Blunkett, in his zeal for citizenship in the curriculum, disregarded the need for an informed understanding of the past.