OK, I've gone through my 7800 cartridges and have found the following variations:
- Choplifter: Copyright text in plain text (rarity guide label pic is in italics)
- Galaga: Copyright text in plain text (rarity guide label pic is in italics)
- Hat Trick: Last text line has "CX7829" left-justified and "Printed in Hong Kong" right-justified; end label lacks "CA..." number (rarity guide has "Printed.." on left, CX# centered, and "CA400067-029" on right)
- Robotron 2084: Copyright text in italics (rarity guide label pic is in plain text)
- Tower Toppler: Last line of text has "Made in China" on left; end label has all black text (rarity guide has "Printed in Taiwan" on left; end label has title in maroon)
- Xevious: Label picture's sky is light grey and other coloring/contrast variations, title logo has a drop-shadow, Copyright date is 1987, "Printed..." text is slanted (Label picture's sky is black, title logo's drop-shadow almost completely blended into picture, Copyright date is 1986, "Printed.." text is normal)
The thing is, like all of the Atari carts made without connector covers, there's two almost rectangular holes on the label side (which the label covers). The labels on Choplifter, Galaga, and Xevious have these holes punched through as well as the screwhole uncovered.
As usual, if you need scans, I can scan them in.