Instances where unnamed characters were named after all

Cafe Society
61

High Plains Drifter:

The next morning, the Stranger rides past Mordecai in the cemetery. Mordecai says: “You know, I never did know your name.” The Stranger replies: “Yes, you do.” As the Stranger rides off into the desert, a perplexed Mordecai stands beside the tombstone he has just finished engraving: “Marshal Jim Duncan, Rest in Peace”.

But it wasn’t a tombstone. It was a wooden cross. Sloppy, Wikipedia!

62

What is interesting with Mr. Spock is This Side of Paradise implies that Spock is his last name and he says his “other name” is unpronounceable but Journey to Babel implies that Spock is his first name and his family name is what is unpronounceable.