A note from my pal Mark Waid about this ASK me entry…
If I may offer: There's another, lesser reason why additional inkers who stepped in for a last-minute save (particularly at Marvel in the '70s, but certainly elsewhere) sometimes weren't credited: as a general rule, the lettering — and, thus, the anticipated credits — was applied to the boards before the inks, unlike today. And since Marvel in the '70s was a pretty loosey-goosey and down-to-the-wire operation in the editorial sense, what with so many writers editing their own books, I imagine there often wasn't the time, thought, or motivation to go to the trouble of amending the credits, yes? I know you know this, and I know it probably doesn't answer the question about Verpoorten and Colletta since John was also the production manager, but I felt it was worth mentioning.
A good point. Marvel was quite understaffed at the time — and to be honest, at later periods when they weren't understaffed, things still slipped by. I told a story about one incident in this post and something like that happened almost every day.
Here's one more example of many: It's Fantastic Four Special #5, which came out in 1967. When the story was lettered, which was before it was inked, they were planning to have it inked by Joe Sinnott. I dunno how well you can see it on your screen but they lettered Joe's name into the credits…
…and then for reasons long forgotten, they wound up having the story inked by Frank Giacoia. When the issue went to press, no one thought to change the credits — so there's Sinnott's name on a story he never touched.
For a long time, I would get calls from folks at Marvel seeking my expertise-of-dubious-value to ask who had drawn or inked or otherwise worked on a certain issue or cover about which they weren't sure. I would often answer the question, assuming I could, then tell the caller, "By the way…you just reprinted the lead story from Fantastic Four Special #5 and the credits on it are still wrong."
The nice person on the phone would (of course) say, "Oh, thanks. I'll make sure that gets changed in our records" and I don't know if it has been. At least once well after one of those calls, they reprinted it again with the wrong credits and paid the reprint fee to Joe Sinnott who I'm sure didn't notice. There were lots of times the published credits were wrong or incomplete.
Mark Waid and I will be doing one of our "Two Marks Explain Everything" panels at Comic-Con International in a few weeks. This is a panel based on the premise that if you have a question about how the comic book industry works — or ever did work — or even why it didn't work — and neither Mark nor I can answer it, no one can. This panel was a big hit at the last WonderCon and if you're at Comic-Con in San Diego on Friday, July 25 and you're anywhere near Room 10 of the San Diego Convention Center at 2:30 PM, Mark Waid and I will be in that room. There, we'll be answering to the best of our abilities, questions about things which will only matter to the kind of person who'd willingly attend a panel like that.
In fact, I'll be in that room from 12:30 PM until 5:30 PM that day hosting panels that fall roughly under the category of Comic Book or Strip History…five of 'em, back-to-back. So don't complain there's nothing in the convention programming about comic books…and that's just what I'm doing on Friday.