Figured I should post a couple pictures of what I think ghosts should look like. The first pictures shows a Griswold finger hinge paddle fully marked with the patents. The top picture is a Griswold Victor scissor hinge (scissor followed finger). You can see faint ghosting of the patent numbers on the Victor paddle. You would never know exactly what it says unless you have the early version to compare with.
Note how the ghost is "soft" looking and not at all consistent - some portions you can make out, others not. That's evidence of a softer filler material coming out in an uneven manner.
The next picture is a plett pan, made most likely in the 1970s at the Wagner Sidney Foundry. The pan should just say "Made In USA", but there is a ghost of the Griswold logo in the center and up on the top two cups, NO, and on the right, 34 (not showing on this pan).
The next picture shows this plett pan before they removed the markings and replaced it with Made In USA. Again a Sidney product.
And one last, and my favorite, ghost. Ghosting of the Griswold markings on an aluminum waffle iron made by TACU (The Aluminum Cooking Utensil Co.). Griswold had them make some of their aluminum products, but this is after, when TACU went out on their own. Now this ghost does exhibit some clear lettering, similar to the 378 ghost, but overall, it is soft and uneven.
I'm still of the opinion the 378 ghost on the Griswold skillet is "off".
You can click on the images to view them larger.
Tom
p.s. As is always the case, just my opinion ;)
Compare this to the ghost on the eBay item.