I just saw this episode on cable, it was the pilot for the show. Interestingly the show was called "Solo" at the beginning of this episode. They must have subsequently renamed it "The Man from U.N.C.L.E." Leo G. Carroll did not appear in this episode. The head of U.N.C.L.E. was called Mr. Allison in this episode and was played by Will Kuluva. I notice that it notes "scenes deleted" next to his name on the "Vulcan Affair" page, but the version I saw did have Mr. Kuluva's scenes in it. David McCallum's Ilya character had a very small role in this episode. I also noticed that this episode included the scene with Solo getting shot at while behind a piece of bulletproof glass. They used this in the intro to the show in later episodes.
Review of The Vulcan Affair
