A few thoughts on the House card that I hope will clarify some stuff.
The general process -
Original art photographed through filters to separate colors and through a screen to make the halftone for each color.
Produces single color negatives (Black and white film, but big. )
Those negatives are put together on an opaque paper or plastic sheet. Most likely paper in 52.
That is the mask, essentially a full sheet sized negative. One for each color.
Flaws in that negative can be fixed in a few ways, specks from dust in the air getting photographed can be painted over with a red colored version of whiteout. (What a fun day that was.... ) Larger mistakes can be covered with a special red cellotape.
Stuff that should print but didn't come out can be drawn in by hand by scratching off some emulsion. It's possible, but sloppy. The place I was I think they'd redo whatever had gone wrong.
Those Masks are used in a special machine to expose the plate which gets developed, checked then sent to the press room to be put on the press and printed.
On the press, a few maybe more copies are run on scrap paper (make ready sheets) to make sure the inking is right, the registration is adjusted properly etc.
Then the actual production sheets are printed.
Stoning off is done to remove something on the plate that is printing but shouldn't.
Something like the House can happen a lot of different ways.
The original art is usually held flat behind glass, if that glass has some stuff on it, hand print or something, a bit of it may not photograph well enough to show up. That's something we would have redone, as it's not really fixable in any practical way.
More likely is stuff on the glass holder for the mask in the plate exposing machine. That has essentially the same result, see the 90 Frank Thomas NNOF and related cards.
That's also not exactly fixable, parts of the red wouldn't print , leaving the neck looking green.
Making that even more probable is that the ones with green show some red in the logo, so whatever was on the glass wasn't solidly opaque like what was probably tape for the NNOF.
For production work with a deadline, that would probably be acceptable. Meaning they knew, and decided to fix it later.
The normal neck missing red may have come first. To me that one looks like they messed up and covered over the log on the red mask.
The negatives they did probably all showed some of the logo, and parts would have been blocked off on different colors. Blocking what shouldn't have been blocked (Or not blocking it off which is almost for sure what caused the black star on Campos) leaves an unprinted area with the rest being normal.
The red could have been stoned off the red plate to "fix" the logo, but I'm not sure why they would.
Plate wear can also affect stuff printing or not, the areas that print are slightly raised above the plate surface. We never did a big enough run for it to be a problem.
The correct version would be from further red plates (Or both earlier and later ones than the mistakes) where the glass in the plate exposer was cleaned so everything came out right.
Someone may or may not have gotten a talking to about it. Depending on if they ran the bad plate until it was time to replace it, or if they replaced it quickly.*
* Dammit Dave! Thats the second time this month your glazed donut frosting has messed up a plate. Don't let it happen again!
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