There are two versions of the counterfeit card, v1 the background grid is visible throughout the sunburst while v2 the sunburst is too bright and it cannot be see.
There is no assortment number, etc. in the lower right of the card on the counterfeits.
Frenzys artwork positioning is incorrect, on the v2 card the easy tell is that the tip of the thruster gun should be under the 'R' not alongside. See image above.
The tech specs preforation line should be a T junction between each figures tech specs (under the proof of authenticity), on the counterfeits it appears disjointed.
The copyright of the counterfeits ends in Takara Co Ltd, Tokyo - this is the same as the 1986 card? (if it ends in Tokyo, Japan its original).
Figure Guide:
The screws/rivets in Rumble's arms are flat and shiny on the counterfeit, instead of dark and with a hole in the center. See the Rumble/Ravage or Frenzy/Laserbeak ID guides for more information on this.
Real Frenzys in real Frenzy/Ratbat sets *only* comes with dark hips, so the trick with dark hips from the Frenzy/Laserbeak guide does not work with Frenzy/Ratbat.
On the counterfeit, Ratbat is the painted details version with silver weapons. The painted version is supposed to come with gold weapons. On Asst card #5733/5734. (Tokyo, Japan card)