Aside from Trek and Man from Uncle I don't know much about Ireland's career in the 60s. But the hair can be from a cap, and the face from a high-res shot from a completely different source... (which is what I would do, if it were me). ETA: however, it occurs to me that the artist could have simply capped the shot himself from the DVDs, which is why you can't find it at TrekCore. When a fan site caps images, they tend to concentrate on the series regulars, rather than the guest stars. I'm sure it's possible that shot was from the ep, just not in a cap in the TrekCore galleries?