Above is a panel from Gold Key's The Man from UNCLE 3, pencilled by George Tuska.
Following up on Mark Evanier's comment about likenesses: although in some cases the license holders insisted on extra work for that fidelity, in other cases the contracts forbade comic books from using likenesses. After the comic book's first two issues, the powers-that-were recognized the popularity of David McCallum's character Illya Kuryakin, and so he and Leo G. Carroll's Alexander Waverly became recognizable in the comics. In those first issues, only Napoleon Solo's face was reinked or redrawn, for the sake of Robert Vaughn's likeness—as in the Tuska panels below, from #2.
On the entire series, it looks to me as if Mike Peppe inked more than the Sekowsky issues attributed to him previously; I'm not sure if #1-2, apart from the Solo faces, were inked by someone other than pencillers Heck and Tuska respectively. (Update: read Mark's comment on this post.)
If Marshall McClintock wrote the Man from UNCLE for Gold Key as the Who's Who says, he didn't do final scripts; they're all by Paul S. Newman or Dick Wood. Wood's are filled with his trademark exclamations such as "Great suffering Hannah." Wood errs in his first script, as many have, by referring to UNCLE as the United Network Command for Law Enforcement—it's the United Network Command for Law and Enforcement.
Man from UNCLE Written by Paul S. Newman
|May/65||#1||The Explosive Affair||p: Don Heck i: ?|
|Oct/65||#2||The Fortune Cookie Affair||p: George Tuska i: ?|
Written by Dick Wood, Inked by Mike Peppe
|Nov/65||#3||The Deadly Devices Affair||p: pg. 1-26 Tuska, pg. 27-32 Heck|
|Jan/66||#4||The Rip Van Solo Affair||p: Werner Roth|
|Mar/66||#5||The Ten Little Uncles Affair||p: Heck|
|May/66||#6||The Three Blind Mice Affair||p: Mike Sekowsky|
|July/66||#7||The Pixilated Puzzle Affair||p: Sekowsky|
|Sept/66||#8||The Floating People Affair||p: Sekowsky|
|Nov/66||#9||The Spirit of St. Louis Affair||p: Sekowsky|
|Jan/67||#10||The Trojan Horse Affair||p: Sekowsky|
|Mar/67||#11||The Three-Story Giant Affair||p: Sekowsky|
|May/67||#12||The Dead Man's Diary Affair||p: Sekowsky|
|July/67||#13||The Flying Clowns Affair||p: Sekowsky|
|Sept/67||#14||The Brain Drain Affair||p: Sekowsky|
|Nov/67||#15||The Animal Agents Affair||p: Tom Gill|
|Jan/68||#16||The Instant Disaster Affair||p: Gill|
|Mar/68||#17||The Deadly Visions Affair||p: Mike Roy|
|May/68||#18||The Alien Affair||p: Roy|
|July/68||#19||The Knight in Shining Armor Affair||p: Roy|
|Oct/68||#20||The Deep Freeze Affair||p: Roy|
The Man from UNCLE stories in #21 and 22 were reprints. #5-8 were reprinted in the British Man from UNCLE World Adventure Library in late 1966.