If the name was memorable enough for him to remember so many years later, I bet he knew how to spell it. When you’re in a class with someone, there are plenty of opportunities to see how your classmates spell their names. Indeed, you often see their names written before you hear anyone use them.
I remember reading in Bill Bryson’s The Mother Tongue that the name “Miller” in America was most commonly the Anglification of the German surname “Mueller” (or “Müller”) by German immigrants, not as much a direct import from English colonists, because English village millers had a reputation for unjust weights and general greed. Bryson’s analogy was the modern lack of the occupational surname “Landlord”.
I can’t testify to the accuracy of his assertion (and I know he’s been criticised some for dubious scholarship in his popular books), but it’s an amusing theory.
Going back to feudal times, wouldn’t “land - lord” be redundant? What else would a lord be? How many landlords were not lords back then, other than the obvious ones like holders of church land like abbeys? (The lead actor in Hawaii Five-Oh was Jack Lord…)
But a landlord isn’t a landed lord (and there were non-landed titles as well, in some places), it’s someone who rents out housing. Completely different thing.