I have often noted how I wish Illya had kept his Russian-ness through subsequent seasons of MFU.

Ah, but the Cold War times, the censors, a dip in writing at points during the run of the show, and the extraordinary popularity of McCallum on par with the Beatles (and thus sort of mushed in many ways with the wild popularity of anything British in the 1960s in the U.S.) kind of the short-circuited that.